The syzkaller USB fuzzer found a general-protection-fault bug in the
yurex driver. The fault occurs when a device has been unplugged; the
driver's interrupt-URB handler logs an error message referring to the
device by name, after the device has been unregistered and its name
deallocated.
This problem is caused by the fact that the interrupt URB isn't
cancelled until the driver's private data structure is released, which
can happen long after the device is gone. The cure is to make sure
that the interrupt URB is killed before yurex_disconnect() returns;
this is exactly the sort of thing that usb_poison_urb() was meant for.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: syzbot+2eb9121678bdb36e6d57@syzkaller.appspotmail.com CC: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
[ Note: this is a further correction / addition of the previous
pin-based quirks for Dell machines; another entry for ALC236 with
the d-mic pin 0x12 and an entry for ALC295 -- tiwai ]
Fixes: b26e36b7ef36 ("ALSA: hda/realtek - add two more pin configuration sets to quirk table") Signed-off-by: Kailang Yang <kailang@realtek.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
When CONFIG_KASAN is set, we can use relatively large amounts of kernel
stack space:
net/caif/cfctrl.c:555:1: warning: the frame size of 1600 bytes is larger than 1280 bytes [-Wframe-larger-than=]
This adds convenience wrappers around cfpkt_extr_head(), which is responsible
for most of the stack growth. With those wrapper functions, gcc apparently
starts reusing the stack slots for each instance, thus avoiding the
problem.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
A compiler can optimize away memset calls by replacing them with mov
instructions. There are KASAN tests that specifically test that KASAN
correctly handles memset calls so we don't want this optimization to
happen.
The solution is to add -fno-builtin flag to test_kasan.ko
Link: http://lkml.kernel.org/r/105ec9a308b2abedb1a0d1fdced0c22d765e4732.1519924383.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Nick Terrell <terrelln@fb.com> Cc: Chris Mason <clm@fb.com> Cc: Yury Norov <ynorov@caviumnetworks.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Jeff Layton <jlayton@redhat.com> Cc: "Jason A . Donenfeld" <Jason@zx2c4.com> Cc: Kostya Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Variable real_size is initialized with a value that is never read, it is
re-assigned a new value later on, hence the initialization is redundant
and can be removed.
Cleans up clang warning:
lib/test_kasan.c:422:21: warning: Value stored to 'real_size' during its initialization is never read
Link: http://lkml.kernel.org/r/20180206144950.32457-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
In rxrpc_destroy_all_calls(), there are two phases: (1) make sure the
->calls list is empty, emitting error messages if not, and (2) wait for the
RCU cleanup to happen on outstanding calls (ie. ->nr_calls becomes 0).
To avoid taking the call_lock, the function prechecks ->calls and if empty,
it returns to avoid taking the lock - this is wrong, however: it still
needs to go and do the second phase and wait for ->nr_calls to become 0.
Without this, the rxrpc_net struct may get deallocated before we get to the
RCU cleanup for the last calls. This can lead to:
Note the "61" at offset 0x58. This corresponds to the ->nr_calls member of
struct rxrpc_net (which is >9k in size, and thus allocated out of the 16k
slab).
Fix this by flipping the condition on the if-statement, putting the locked
section inside the if-body and dropping the return from there. The
function will then always go on to wait for the RCU cleanup on outstanding
calls.
Fixes: 2baec2c3f854 ("rxrpc: Support network namespacing") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The line6 driver uses a lot of USB buffers off of the stack, which is
not allowed on many systems, causing the driver to crash on some of
them. Fix this up by dynamically allocating the buffers with kmalloc()
which allows for proper DMA-able memory.
In the bnxt_init_one() error path, short FW command request memory
is not freed. This patch fixes it.
Fixes: e605db801bde ("bnxt_en: Support for Short Firmware Message") Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com> Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The driver builds a list of multicast addresses and sends it to the
firmware when the driver's ndo_set_rx_mode() is called. In rare
cases, the firmware can fail this call if internal resources to
add multicast addresses are exhausted. In that case, we should
try the call again by setting the ALL_MCAST flag which is more
guaranteed to succeed.
Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.") Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Packet sockets in datagram mode take a destination address. Verify its
length before passing to dev_hard_header.
Prior to 2.6.14-rc3, the send code ignored sll_halen. This is
established behavior. Directly compare msg_namelen to dev->addr_len.
Change v1->v2: initialize addr in all paths
Fixes: 6b8d95f1795c4 ("packet: validate address length if non-zero") Suggested-by: David Laight <David.Laight@aculab.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
As it shows, the first sctp_do_sm() running under atomic context (NET_RX
softirq) invoked sctp_primitive_ASCONF() that uses GFP_KERNEL flag later,
and this flag is supposed to be used in non-atomic context only. Besides,
sctp_do_sm() was called recursively, which is not expected.
Vlad tried to fix this recursive call in Commit c0786693404c ("sctp: Fix
oops when sending queued ASCONF chunks") by introducing a new command
SCTP_CMD_SEND_NEXT_ASCONF. But it didn't work as this command is still
used in the first sctp_do_sm() call, and sctp_primitive_ASCONF() will
be called in this command again.
To avoid calling sctp_do_sm() recursively, we send the next queued ASCONF
not by sctp_primitive_ASCONF(), but by sctp_sf_do_prm_asconf() in the 1st
sctp_do_sm() directly.
Reported-by: Ying Xu <yinxu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
marvell_get_sset_count() returns how many statistics counters there
are. If the PHY supports fibre, there are 3, otherwise two.
marvell_get_strings() does not make this distinction, and always
returns 3 strings. This then often results in writing past the end
of the buffer for the strings.
Fixes: 2170fef78a40 ("Marvell phy: add field to get errors from fiber link.") Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The "fs->location" is a u32 that comes from the user in ethtool_set_rxnfc().
We can't pass unclamped values to test_bit() or it results in an out of
bounds access beyond the end of the bitmap.
Fixes: 7318166cacad ("net: dsa: bcm_sf2: Add support for ethtool::rxnfc") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Canonical way to fetch sk_user_data from an encap_rcv() handler called
from UDP stack in rcu protected section is to use rcu_dereference_sk_user_data(),
otherwise compiler might read it multiple times.
Fixes: d00fa9adc528 ("il2tp: fix races with tunnel socket close") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Fixes: 54652eb12c1b ("l2tp: hold tunnel while looking up sessions in l2tp_netlink") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
A request for a flowlabel fails in process or user exclusive mode must
fail if the caller pid or uid does not match. Invert the test.
Previously, the test was unsafe wrt PID recycling, but indeed tested
for inequality: fl1->owner != fl->owner
Fixes: 4f82f45730c68 ("net ip6 flowlabel: Make owner a union of struct pid* and kuid_t") Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Memory state around the buggy address: ffff888094012900: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff888094012980: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
>ffff888094012a00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
^ ffff888094012a80: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff888094012b00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
Fixes: 4f82f45730c6 ("net ip6 flowlabel: Make owner a union of struct pid * and kuid_t") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Previously, during fragmentation after forwarding, skb->skb_iif isn't
preserved, i.e. 'ip_copy_metadata' does not copy skb_iif from given
'from' skb.
As a result, ip_do_fragment's creates fragments with zero skb_iif,
leading to inconsistent behavior.
Assume for example an eBPF program attached at tc egress (post
forwarding) that examines __sk_buff->ingress_ifindex:
- the correct iif is observed if forwarding path does not involve
fragmentation/refragmentation
- a bogus iif is observed if forwarding path involves
fragmentation/refragmentatiom
Fix, by preserving skb_iif during 'ip_copy_metadata'.
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
valid_phys_addr_range() is used to sanity check the physical address range
of an operation, e.g., access to /dev/mem. It uses __pa(high_memory)
internally.
If memory is populated at the end of the physical address space, then
__pa(high_memory) is outside of the physical address space because:
For the comparison in valid_phys_addr_range() this is not an issue, but if
CONFIG_DEBUG_VIRTUAL is enabled, __pa() maps to __phys_addr(), which
verifies that the resulting physical address is within the valid physical
address space of the CPU. So in the case that memory is populated at the
end of the physical address space, this is not true and triggers a
VIRTUAL_BUG_ON().
Use __pa(high_memory - 1) to prevent the conversion from going beyond
the end of valid physical addresses.
Fixes: be62a3204406 ("x86/mm: Limit mmap() of /dev/mem to valid physical addresses") Signed-off-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Craig Bergstrom <craigb@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hans Verkuil <hans.verkuil@cisco.com> Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sander Eikelenboom <linux@eikelenboom.it> Cc: Sean Young <sean@mess.org> Link: https://lkml.kernel.org/r/20190326001817.15413-2-rcampbell@nvidia.com Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
There are a few windows during AER/EEH when we can access PCIe I/O mapped
registers. This will harden the access to insure we do not allow PCIe
access during errors
Signed-off-by: Dave Carroll <david.carroll@microsemi.com> Reviewed-by: Sagar Biradar <sagar.biradar@microchip.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The fix is to obviously take the srcu lock, just like we do on the
read side of things since bf308242ab98. One wonders why this wasn't
fixed at the same time, but hey...
Fixes: bf308242ab98 ("KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
We've become very cautious to now always reset the vcpu when nothing
is loaded on the physical CPU. To do so, we now disable preemption
and do a kvm_arch_vcpu_put() to make sure we have all the state
in memory (and that it won't be loaded behind out back).
This now causes issues with resetting the PMU, which calls into perf.
Perf itself uses mutexes, which clashes with the lack of preemption.
It is worth realizing that the PMU is fully emulated, and that
no PMU state is ever loaded on the physical CPU. This means we can
perfectly reset the PMU outside of the non-preemptible section.
Fixes: e761a927bc9a ("KVM: arm/arm64: Reset the VCPU without preemption and vcpu state loaded") Reported-by: Julien Grall <julien.grall@arm.com> Tested-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
There are a few system calls (pselect, ppoll, etc) which replace a task
sigmask while they are running in a kernel-space
When a task calls one of these syscalls, the kernel saves a current
sigmask in task->saved_sigmask and sets a syscall sigmask.
On syscall-exit-stop, ptrace traps a task before restoring the
saved_sigmask, so PTRACE_GETSIGMASK returns the syscall sigmask and
PTRACE_SETSIGMASK does nothing, because its sigmask is replaced by
saved_sigmask, when the task returns to user-space.
This patch fixes this problem. PTRACE_GETSIGMASK returns saved_sigmask
if it's set. PTRACE_SETSIGMASK drops the TIF_RESTORE_SIGMASK flag.
Link: http://lkml.kernel.org/r/20181120060616.6043-1-avagin@gmail.com Fixes: 29000caecbe8 ("ptrace: add ability to get/set signal-blocked mask") Signed-off-by: Andrei Vagin <avagin@gmail.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Backspace is not working on some terminal emulators which do not send the
key code defined by terminfo. Terminals either send '^H' (8) or '^?' (127).
But currently only '^?' is handled. Let's also handle '^H' for those
terminals.
If the call to of_gpiochip_scan_gpios() in of_gpiochip_add() fails, no
error handling is performed. This lead to the need of callers to call
of_gpiochip_remove() on failure, which causes "BAD of_node_put() on ..."
if the failure happened before the call to of_node_get().
Fix this by adding proper error handling.
Note that calling gpiochip_remove_pin_ranges() multiple times causes no
harm: subsequent calls are a no-op.
If an incoming ELS of type RSCN contains more than one element, zfcp
suboptimally causes repeated erp trigger NOP trace records for each
previously failed port. These could be ports that went away. It loops over
each RSCN element, and for each of those in an inner loop over all
zfcp_ports.
The trigger to recover failed ports should be just the reception of some
RSCN, no matter how many elements it has. So we can loop over failed ports
separately, and only then loop over each RSCN element to handle the
non-failed ports.
The call chain was:
zfcp_fc_incoming_rscn
for (i = 1; i < no_entries; i++)
_zfcp_fc_incoming_rscn
list_for_each_entry(port, &adapter->port_list, list)
if (masked port->d_id match) zfcp_fc_test_link
if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <===
In order the reduce the "flooding" of the REC trace area in such cases, we
factor out handling the failed ports to be outside of the entries loop:
zfcp_fc_incoming_rscn
if (no_entries > 1) <===
list_for_each_entry(port, &adapter->port_list, list) <===
if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <===
for (i = 1; i < no_entries; i++)
_zfcp_fc_incoming_rscn
list_for_each_entry(port, &adapter->port_list, list)
if (masked port->d_id match) zfcp_fc_test_link
Abbreviated example trace records before this code change:
Tag : fcrscn1
WWPN : 0x500507630310d327
ERP want : 0x02
ERP need : 0x02
Tag : fcrscn1
WWPN : 0x500507630310d327
ERP want : 0x02
ERP need : 0x00 NOP => superfluous trace record
The last trace entry repeats if there are more than 2 RSCN elements.
Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
meson_drv_bind() registers a meson_drm struct as the device's privdata,
but meson_drv_unbind() tries to retrieve a drm_device. This may cause a
segfault on shutdown:
The call to of_get_child_by_name returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
Detected by coccinelle with the following warnings:
./drivers/net/ethernet/ti/netcp_ethss.c:3661:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 3654, but without a corresponding object release within this function.
./drivers/net/ethernet/ti/netcp_ethss.c:3665:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 3654, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Cc: Wingman Kwok <w-kwok2@ti.com> Cc: Murali Karicheri <m-karicheri2@ti.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The call to ehea_get_eth_dn returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
Detected by coccinelle with the following warnings:
./drivers/net/ethernet/ibm/ehea/ehea_main.c:3163:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 3154, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Cc: Douglas Miller <dougmill@linux.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The call to of_parse_phandle returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
Detected by coccinelle with the following warnings:
./drivers/net/ethernet/xilinx/xilinx_axienet_main.c:1624:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1569, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Cc: Anirudha Sarangi <anirudh@xilinx.com> Cc: John Linn <John.Linn@xilinx.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michal Simek <michal.simek@xilinx.com> Cc: netdev@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Specifying a retrans=0 mount parameter to a NFS/TCP mount, is
inadvertently causing the NFS client to rewrite any specified
timeout parameter to the default of 60 seconds.
Fixes: a956beda19a6 ("NFS: Allow the mount option retrans=0") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
callers of tcf_gact_goto_chain_index() can potentially read an old value
of the chain index, or even dereference a NULL 'goto_chain' pointer,
because 'goto_chain' and 'tcfa_action' are read in the traffic path
without caring of concurrent write in the control path. The most recent
value of chain index can be read also from a->tcfa_action (it's encoded
there together with TC_ACT_GOTO_CHAIN bits), so we don't really need to
dereference 'goto_chain': just read the chain id from the control action.
Fixes: e457d86ada27 ("net: sched: add couple of goto_chain helpers") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Both PCLK and HCLK are "required" clocks according to macb devicetree
documentation. There is a chance that devm_clk_get doesn't return a
negative error but just a NULL clock structure instead. In such a case
the driver proceeds as usual and uses pclk value 0 to calculate MDC
divisor which is incorrect. Hence fix the same in clock initialization.
Signed-off-by: Harini Katakam <harini.katakam@xilinx.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
phydm.internal is allocated using kzalloc which is used multiple
times without a check for NULL pointer. This patch avoids such a
scenario by returning 0, consistent with the failure case.
This code is obviously not useful, but so far as I can tell
"pcmd->cmdcode" is never GEN_CMD_CODE(_Read_BBREG) so it's not harmful
either. For now the easiest fix is to just call r8712_free_cmd_obj()
and return.
Fixes: 2865d42c78a9 ("staging: r8712u: Add the new driver to the mainline kernel") Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
hwxmits is allocated via kcalloc and not checked for failure before its
dereference. The patch fixes this problem by returning error upstream
in rtl8723bs, rtl8188eu.
Signed-off-by: Aditya Pakki <pakki001@umn.edu> Acked-by: Mukesh Ojha <mojha@codeaurora.org> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The ks8851 chip's initial carrier state is down. A Link Change Interrupt
is signaled once interrupts are enabled if the carrier is up.
The ks8851 driver has it backwards by assuming that the initial carrier
state is up. The state is therefore misrepresented if the interface is
opened with no cable attached. Fix it.
The Link Change interrupt is sometimes not signaled unless the P1MBSR
register (which contains the Link Status bit) is read on ->ndo_open().
This might be a hardware erratum. Read the register by calling
mii_check_link(), which has the desirable side effect of setting the
carrier state to down if the cable was detached while the interface was
closed.
Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Frank Pavlic <f.pavlic@kunbus.de> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Tristram Ha <Tristram.Ha@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The ks8851 driver currently requests the IRQ before registering the
net_device. Because the net_device name is used as IRQ name and is
still "eth%d" when the IRQ is requested, it's impossibe to tell IRQs
apart if multiple ks8851 chips are present. Most other drivers delay
requesting the IRQ until the net_device is opened. Do the same.
The driver doesn't enable interrupts on the chip before opening the
net_device and disables them when closing it, so there doesn't seem to
be a need to request the IRQ already on probe.
Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Frank Pavlic <f.pavlic@kunbus.de> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Tristram Ha <Tristram.Ha@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Commit 73fdeb82e963 ("net: ks8851: Add optional vdd_io regulator and
reset gpio") amended the ks8851 driver to briefly assert the chip's
reset pin on probe. It also amended the probe routine's error path to
reassert the reset pin if a subsequent initialization step fails.
However the commit misplaced reassertion of the reset pin in the error
path such that it is not performed if the check of the Chip ID and
Enable Register (CIDER) fails. The error path is therefore slightly
asymmetrical to the probe routine's body. Fix it.
Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Frank Pavlic <f.pavlic@kunbus.de> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Nishanth Menon <nm@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The ks8851 driver lets the chip auto-dequeue received packets once they
have been read in full. It achieves that by setting the ADRFE flag in
the RXQCR register ("Auto-Dequeue RXQ Frame Enable").
However if allocation of a packet's socket buffer or retrieval of the
packet over the SPI bus fails, the packet will not have been read in
full and is not auto-dequeued. Such partial retrieval of a packet
confuses the chip's RX queue management: On the next RX interrupt,
the first packet read from the queue will be the one left there
previously and this one can be retrieved without issues. But for any
newly received packets, the frame header status and byte count registers
(RXFHSR and RXFHBCR) contain bogus values, preventing their retrieval.
The chip allows explicitly dequeueing a packet from the RX queue by
setting the RRXEF flag in the RXQCR register ("Release RX Error Frame").
This could be used to dequeue the packet in case of an error, but if
that error is a failed SPI transfer, it is unknown if the packet was
transferred in full and was auto-dequeued or if it was only transferred
in part and requires an explicit dequeue. The safest approach is thus
to always dequeue packets explicitly and forgo auto-dequeueing.
Without this change, I've witnessed packet retrieval break completely
when an SPI DMA transfer fails, requiring a chip reset. Explicit
dequeueing magically fixes this and makes packet retrieval absolutely
robust for me.
The chip's documentation suggests auto-dequeuing and uses the RRXEF
flag only to dequeue error frames which the driver doesn't want to
retrieve. But that seems to be a fair-weather approach.
Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Frank Pavlic <f.pavlic@kunbus.de> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Tristram Ha <Tristram.Ha@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Increase the reset duration to ensure correct phy functionality. The
reset duration is taken from barebox commit 52fdd510de ("ARM: dts:
pfla02: use long enough reset for ethernet phy"):
Use a longer reset time for ethernet phy Micrel KSZ9031RNX. Otherwise a
small percentage of modules have 'transmission timeouts' errors like
barebox@Phytec phyFLEX-i.MX6 Quad Carrier-Board:/ ifup eth0
warning: No MAC address set. Using random address 7e:94:4d:02:f8:f3
eth0: 1000Mbps full duplex link detected
eth0: transmission timeout
T eth0: transmission timeout
T eth0: transmission timeout
T eth0: transmission timeout
T eth0: transmission timeout
Cc: Stefan Christ <s.christ@phytec.de> Cc: Christian Hemp <c.hemp@phytec.de> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> Fixes: 3180f956668e ("ARM: dts: Phytec imx6q pfla02 and pbab01 support") Signed-off-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Restore the status of ep->stopped in function net2272_dequeue().
When the given request is not found in the endpoint queue
the function returns -EINVAL without restoring the state of
ep->stopped. Thus the endpoint keeps blocked and does not transfer
any data anymore.
This fix is only compile-tested, since we do not have a
corresponding hardware. An analogous fix was tested in the sibling
driver. See "usb: gadget: net2280: Fix net2280_dequeue()"
Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
When a request must be dequeued with net2280_dequeue() e.g. due
to a device clear action and the same request is finished by the
function scan_dma_completions() then the function net2280_dequeue()
does not find the request in the following search loop and
returns the error -EINVAL without restoring the status ep->stopped.
Thus the endpoint keeps blocked and does not receive any data
anymore.
This fix restores the status and does not issue an error message.
Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
The OUT endpoint normally blocks (NAK) subsequent packets when a
short packet was received and returns an incomplete queue entry to
the gadget driver. Thereby the gadget driver can detect a short packet
when reading queue entries with a length that is not equal to a
multiple of packet size.
The start_queue() function enables receiving OUT packets regardless of
the content of the OUT FIFO. This results in a race: With the current
code, it's possible that the "!ep->is_in && (readl(&ep->regs->ep_stat)
& BIT(NAK_OUT_PACKETS))" test in start_dma() will fail, then a short
packet will be received, and then start_queue() will call
stop_out_naking(). That's what we don't want (OUT naking gets turned
off while there is data in the FIFO) because then the next driver
request might receive a mixture of old and new packets.
With the patch, this race can't occur because the FIFO's state is
tested after we know that OUT naking is already turned on, and OUT
naking is stopped only when both of the conditions are met. This
ensures that all received data is delivered to the gadget driver,
which can detect a short packet now before new packets are appended
to the last short packet.
Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Andrey has reported on OpenWrt's bug tracking system[1], that he
currently can't use ar93xx_uart as pure serial UART without console
(CONFIG_SERIAL_8250_CONSOLE and CONFIG_SERIAL_AR933X_CONSOLE undefined),
because compilation ends with following error:
ar933x_uart.c: In function 'ar933x_uart_console_write':
ar933x_uart.c:550:14: error: 'struct uart_port' has no
member named 'sysrq'
So this patch moves all the code related to console handling behind
series of CONFIG_SERIAL_AR933X_CONSOLE ifdefs.
The ucast IP table is utilized by some of the L3-specific sysfs attributes
that qeth_l3_create_device_attributes() provides. So initialize the table
_before_ registering the attributes.
Fixes: ebccc7397e4a ("s390/qeth: add missing hash table initializations") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Since Commit 21d1196a35f5 ("ipv4: set transport header earlier"),
skb->transport_header has been always set before entering INET
netfilter. This patch is to set skb->transport_header for bridge
before entering INET netfilter by bridge-nf-call-iptables.
It also fixes an issue that sctp_error() couldn't compute a right
csum due to unset skb->transport_header.
Fixes: e6d8b64b34aa ("net: sctp: fix and consolidate SCTP checksumming code") Reported-by: Li Shuang <shuali@redhat.com> Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
For a 64-bit process the randomization of the program break is quite
large with 1GB. That is as big as the randomization of the anonymous
mapping base, for a test case started with '/lib/ld64.so.1 <exec>'
it can happen that the heap is placed after the stack. To avoid
this limit the program break randomization to 32MB for 64-bit and
keep 8MB for 31-bit.
Reported-by: Stefan Liebler <stli@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount. All
callers converted to handle a failure.
If the page refcount wraps around past zero, it will be freed while
there are still four billion references to it. One of the possible
avenues for an attacker to try to make this happen is by doing direct IO
on a page multiple times. This patch makes get_user_pages() refuse to
take a new page reference if there are already more than two billion
references to the page.
This is the same as the traditional 'get_page()' function, but instead
of unconditionally incrementing the reference count of the page, it only
does so if the count was "safe". It returns whether the reference count
was incremented (and is marked __must_check, since the caller obviously
has to be aware of it).
Also like 'get_page()', you can't use this function unless you already
had a reference to the page. The intent is that you can use this
exactly like get_page(), but in situations where you want to limit the
maximum reference count.
The code currently does an unconditional WARN_ON_ONCE() if we ever hit
the reference count issues (either zero or negative), as a notification
that the conditional non-increment actually happened.
NOTE! The count access for the "safety" check is inherently racy, but
that doesn't matter since the buffer we use is basically half the range
of the reference count (ie we look at the sign of the count).
We have a VM_BUG_ON() to check that the page reference count doesn't
underflow (or get close to overflow) by checking the sign of the count.
That's all fine, but we actually want to allow people to use a "get page
ref unless it's already very high" helper function, and we want that one
to use the sign of the page ref (without triggering this VM_BUG_ON).
Change the VM_BUG_ON to only check for small underflows (or _very_ close
to overflowing), and ignore overflows which have strayed into negative
territory.
During driver initialization the driver sends a reset to the device and
waits for the firmware to signal that it is ready to continue.
Commit d2f372ba0914 ("mlxsw: pci: Increase PCI SW reset timeout")
increased the timeout to 13 seconds due to longer PHY calibration in
Spectrum-2 compared to Spectrum-1.
Recently it became apparent that this timeout is too short and therefore
this patch increases it again to a safer limit that will be reduced in
the future.
Fixes: c3ab435466d5 ("mlxsw: spectrum: Extend to support Spectrum-2 ASIC") Fixes: d2f372ba0914 ("mlxsw: pci: Increase PCI SW reset timeout") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
When STRICT_KERNEL_RWX is enabled, and we're using the radix MMU, we
call radix__change_memory_range() late in boot to change page
protections. We do that both to mark rodata read only and also to mark
init text no-execute. That involves walking the kernel page tables,
and clearing _PAGE_WRITE or _PAGE_EXEC respectively.
With radix we may use hugepages for the linear mapping, so the code in
radix__change_memory_range() uses eg. pmd_huge() to test if it has
found a huge mapping, and if so it stops the page table walk and
changes the PMD permissions.
However if the kernel is built without HUGETLBFS support, pmd_huge()
is just a #define that always returns 0. That causes the code in
radix__change_memory_range() to incorrectly interpret the PMD value as
a pointer to a PTE page rather than as a PTE at the PMD level.
We can see this using `dv` in xmon which also uses pmd_huge():
0:mon> dv c000000000000000
pgd @ 0xc000000001740000
pgdp @ 0xc000000001740000 = 0x80000000ffffb009
pudp @ 0xc0000000ffffb000 = 0x80000000ffffa009
pmdp @ 0xc0000000ffffa000 = 0xc00000000000018f <- this is a PTE
ptep @ 0xc000000000000100 = 0xa64bb17da64ab07d <- kernel text
The end result is we treat the value at 0xc000000000000100 as a PTE
and clear _PAGE_WRITE or _PAGE_EXEC, potentially corrupting the code
at that address.
In Joel's specific case we cleared the sign bit in the offset of the
branch, causing a backward branch to turn into a forward branch which
caused us to branch into a non-executable page. However the exact
nature of the crash depends on kernel version, compiler version, and
other factors.
We need to fix radix__change_memory_range() to not use accessors that
depend on HUGETLBFS, but we also have radix memory hotplug code that
uses pmd_huge() etc that will also need fixing. So for now just
disallow the broken combination of Radix with HUGETLBFS disabled.
The only defconfig we have that is affected is skiroot_defconfig, so
turn on HUGETLBFS there so that it still gets Radix.
Fixes: 566ca99af026 ("powerpc/mm/radix: Add dummy radix_enabled()") Cc: stable@vger.kernel.org # v4.7+ Reported-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Kaby Lake (and Coffee Lake) has PC8/PC9/PC10 residency counters.
This patch updates the list of Kaby/Coffee Lake PMU event counters
from the snb_cstates[] list of events to the hswult_cstates[]
list of events, which keeps all previously supported events and
also adds the PKG_C8, PKG_C9 and PKG_C10 residency counters.
This allows user space tools to profile them through the perf interface.
Signed-off-by: Harry Pan <harry.pan@intel.com> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: gs0622@gmail.com Link: http://lkml.kernel.org/r/20190424145033.1924-1-harry.pan@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Harry Pan [Fri, 9 Mar 2018 12:15:48 +0000 (20:15 +0800)]
perf/x86/intel: Enable C-state residency events for Cannon Lake
BugLink: https://bugs.launchpad.net/bugs/1838459
Cannon Lake supports C1/C3/C6/C7, PC2/PC3/PC6/PC7/PC8/PC9/PC10
state residency counters, this patch enables those counters.
( The MSR information is based on Intel Software Developers' Manual,
Vol. 4, Order No. 335592. )
Tested-by: Puthikorn Voravootivat <puthik@chromium.org> Signed-off-by: Harry Pan <harry.pan@intel.com> Reviewed-by: Benson Leung <bleung@chromium.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan.liang@intel.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: gs0622@gmail.com Link: http://lkml.kernel.org/r/20180309121549.630-3-harry.pan@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit 1159e09476536250c2a0173d4298d15114df7a89) Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Commit b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC
inconsistencies across Y2038") changed the type of wtom_clock_sec
to s64 on PPC64. Therefore, VDSO32 needs to read it with a 4 bytes
shift in order to retrieve the lower part of it.
Fixes: b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038") Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Commit a5681e20b541 ("net/ibmnvic: Fix deadlock problem
in reset") made the change to hold the RTNL lock during
driver reset but still calls netdev_notify_peers, which
results in a deadlock. Instead, use call_netdevice_notifiers,
which is functionally the same except that it does not
take the RTNL lock again.
Fixes: a5681e20b541 ("net/ibmnvic: Fix deadlock problem in reset") Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Florian Westphal [Thu, 30 Aug 2018 08:42:55 +0000 (10:42 +0200)]
netfilter: nf_tables: warn when expr implements only one of activate/deactivate
BugLink: https://bugs.launchpad.net/bugs/1838459
->destroy is only allowed to free data, or do other cleanups that do not
have side effects on other state, such as visibility to other netlink
requests.
Such things need to be done in ->deactivate.
As a transaction can fail, we need to make sure we can undo such
operations, therefore ->activate() has to be provided too.
So print a warning and refuse registration if expr->ops provides
only one of the two operations.
v2: fix nft_expr_check_ops to not repeat same check twice (Jones Desougi)
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
There is a UBSAN report as below:
UBSAN: Undefined behaviour in net/ipv4/tcp_input.c:2877:56
signed integer overflow: 2147483647 * 1000 cannot be represented in type 'int'
CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.1.0-rc4-00058-g582549e #1
Call Trace:
<IRQ>
dump_stack+0x8c/0xba
ubsan_epilogue+0x11/0x60
handle_overflow+0x12d/0x170
? ttwu_do_wakeup+0x21/0x320
__ubsan_handle_mul_overflow+0x12/0x20
tcp_ack_update_rtt+0x76c/0x780
tcp_clean_rtx_queue+0x499/0x14d0
tcp_ack+0x69e/0x1240
? __wake_up_sync_key+0x2c/0x50
? update_group_capacity+0x50/0x680
tcp_rcv_established+0x4e2/0xe10
tcp_v4_do_rcv+0x22b/0x420
tcp_v4_rcv+0xfe8/0x1190
ip_protocol_deliver_rcu+0x36/0x180
ip_local_deliver+0x15b/0x1a0
ip_rcv+0xac/0xd0
__netif_receive_skb_one_core+0x7f/0xb0
__netif_receive_skb+0x33/0xc0
netif_receive_skb_internal+0x84/0x1c0
napi_gro_receive+0x2a0/0x300
receive_buf+0x3d4/0x2350
? detach_buf_split+0x159/0x390
virtnet_poll+0x198/0x840
? reweight_entity+0x243/0x4b0
net_rx_action+0x25c/0x770
__do_softirq+0x19b/0x66d
irq_exit+0x1eb/0x230
do_IRQ+0x7a/0x150
common_interrupt+0xf/0xf
</IRQ>
It can be reproduced by:
echo 2147483647 > /proc/sys/net/ipv4/tcp_min_rtt_wlen
Fixes: f672258391b42 ("tcp: track min RTT using windowed min-filter") Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
If we add a bond device which is already the master of the team interface,
we will hold the team->lock in team_add_slave() first and then request the
lock in team_set_mac_address() again. The functions are called like:
Since there are more IOT2040 variants with identical hardware but
different asset tags, the asset tag matching should be adjusted to
support them.
For the board name "SIMATIC IOT2000", currently there are 2 types of
hardware, IOT2020 and IOT2040. The IOT2020 is identified by its unique
asset tag. Match on it first. If we then match on the board name only,
we will catch all IOT2040 variants. In the future there will be no other
devices with the "SIMATIC IOT2000" DMI board name but different
hardware.
Signed-off-by: Su Bao Cheng <baocheng.su@siemens.com> Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
stmmac_check_ether_addr() checks the MAC address and assigns one in
driver open(). In many cases when we create slave netdevice, the dev
addr is inherited from master but the master dev addr maybe NULL at
that time, so move this call to driver probe so that address is
always valid.
Signed-off-by: Xiaofei Shen <xiaofeis@codeaurora.org> Tested-by: Xiaofei Shen <xiaofeis@codeaurora.org> Signed-off-by: Sneh Shah <snehshah@codeaurora.org> Signed-off-by: Vinod Koul <vkoul@kernel.org> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Before the commit 490ea5967b0d ("RDS: IB: move FMR code to its own file"),
when the dirty_count is greater than 9/10 of max_items of 8K pool,
1M pool is used, Vice versa. After the commit 490ea5967b0d ("RDS: IB: move
FMR code to its own file"), the above is removed. When we make the
following tests.
Server:
rds-stress -r 1.1.1.16 -D 1M
Client:
rds-stress -r 1.1.1.14 -s 1.1.1.16 -D 1M
The following will appear.
"
connecting to 1.1.1.16:4000
negotiated options, tasks will start in 2 seconds
Starting up..header from 1.1.1.166:4001 to id 4001 bogus
..
tsks tx/s rx/s tx+rx K/s mbi K/s mbo K/s tx us/c rtt us
cpu %
1 0 0 0.00 0.00 0.00 0.00 0.00 -1.00
1 0 0 0.00 0.00 0.00 0.00 0.00 -1.00
1 0 0 0.00 0.00 0.00 0.00 0.00 -1.00
1 0 0 0.00 0.00 0.00 0.00 0.00 -1.00
1 0 0 0.00 0.00 0.00 0.00 0.00 -1.00
...
"
So this exchange between 8K and 1M pool is added back.
Fixes: commit 490ea5967b0d ("RDS: IB: move FMR code to its own file") Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Before calling __ip_options_compile(), we need to ensure the network
header is a an IPv4 one, and that it is already pulled in skb->head.
RAW sockets going through a tunnel can end up calling ipv4_link_failure()
with total garbage in the skb, or arbitrary lengthes.
syzbot report :
BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:355 [inline]
BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0x294/0x1120 net/ipv4/ip_options.c:123
Write of size 69 at addr ffff888096abf068 by task syz-executor.4/9204
Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stephen Suryaputra <ssuryaextr@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
In DAX mode a write pagefault can race with write(2) in the following
way:
CPU0 CPU1
write fault for mapped zero page (hole)
dax_iomap_rw()
iomap_apply()
xfs_file_iomap_begin()
- allocates blocks
dax_iomap_actor()
invalidate_inode_pages2_range()
- invalidates radix tree entries in given range
dax_iomap_pte_fault()
grab_mapping_entry()
- no entry found, creates empty
...
xfs_file_iomap_begin()
- finds already allocated block
...
vmf_insert_mixed_mkwrite()
- WARNs and does nothing because there
is still zero page mapped in PTE
unmap_mapping_pages()
This race results in WARN_ON from insert_pfn() and is occasionally
triggered by fstest generic/344. Note that the race is otherwise
harmless as before write(2) on CPU0 is finished, we will invalidate page
tables properly and thus user of mmap will see modified data from
write(2) from that point on. So just restrict the warning only to the
case when the PFN in PTE is not zero page.
Link: http://lkml.kernel.org/r/20180824154542.26872-1-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Commit ce02ef06fcf7 ("x86, retpolines: Raise limit for generating indirect
calls from switch-case") raised the limit under retpolines to 20 switch
cases where gcc would only then start to emit jump tables, and therefore
effectively disabling the emission of slow indirect calls in this area.
After this has been brought to attention to gcc folks [0], Martin Liska
has then fixed gcc to align with clang by avoiding to generate switch jump
tables entirely under retpolines. This is taking effect in gcc starting
from stable version 8.4.0. Given kernel supports compilation with older
versions of gcc where the fix is not being available or backported anymore,
we need to keep the extra KBUILD_CFLAGS around for some time and generally
set the -fno-jump-tables to align with what more recent gcc is doing
automatically today.
More than 20 switch cases are not expected to be fast-path critical, but
it would still be good to align with gcc behavior for versions < 8.4.0 in
order to have consistency across supported gcc versions. vmlinux size is
slightly growing by 0.27% for older gcc. This flag is only set to work
around affected gcc, no change for clang.
From networking side, there are numerous attempts to get rid of indirect
calls in fast-path wherever feasible in order to avoid the cost of
retpolines, for example, just to name a few:
* 283c16a2dfd3 ("indirect call wrappers: helpers to speed-up indirect calls of builtin")
* aaa5d90b395a ("net: use indirect call wrappers at GRO network layer")
* 028e0a476684 ("net: use indirect call wrappers at GRO transport layer")
* 356da6d0cde3 ("dma-mapping: bypass indirect calls for dma-direct")
* 09772d92cd5a ("bpf: avoid retpoline for lookup/update/delete calls on maps")
* 10870dd89e95 ("netfilter: nf_tables: add direct calls for all builtin expressions")
[...]
Recent work on XDP from Björn and Magnus additionally found that manually
transforming the XDP return code switch statement with more than 5 cases
into if-else combination would result in a considerable speedup in XDP
layer due to avoidance of indirect calls in CONFIG_RETPOLINE enabled
builds. On i40e driver with XDP prog attached, a 20-26% speedup has been
observed [0]. Aside from XDP, there are many other places later in the
networking stack's critical path with similar switch-case
processing. Rather than fixing every XDP-enabled driver and locations in
stack by hand, it would be good to instead raise the limit where gcc would
emit expensive indirect calls from the switch under retpolines and stick
with the default as-is in case of !retpoline configured kernels. This would
also have the advantage that for archs where this is not necessary, we let
compiler select the underlying target optimization for these constructs and
avoid potential slow-downs by if-else hand-rewrite.
In case of gcc, this setting is controlled by case-values-threshold which
has an architecture global default that selects 4 or 5 (latter if target
does not have a case insn that compares the bounds) where some arch back
ends like arm64 or s390 override it with their own target hooks, for
example, in gcc commit db7a90aa0de5 ("S/390: Disable prediction of indirect
branches") the threshold pretty much disables jump tables by limit of 20
under retpoline builds. Comparing gcc's and clang's default code
generation on x86-64 under O2 level with retpoline build results in the
following outcome for 5 switch cases:
* gcc with -mindirect-branch=thunk-inline -mindirect-branch-register:
Raising the cases to a high number (e.g. 100) will still result in similar
code generation pattern with clang and gcc as above, in other words clang
generally turns off jump table emission by having an extra expansion pass
under retpoline build to turn indirectbr instructions from their IR into
switch instructions as a built-in -mno-jump-table lowering of a switch (in
this case, even if IR input already contained an indirect branch).
For gcc, adding --param=case-values-threshold=20 as in similar fashion as
s390 in order to raise the limit for x86 retpoline enabled builds results
in a small vmlinux size increase of only 0.13% (before=18,027,528
after=18,051,192). For clang this option is ignored due to i) not being
needed as mentioned and ii) not having above cmdline
parameter. Non-retpoline-enabled builds with gcc continue to use the
default case-values-threshold setting, so nothing changes here.
[0] https://lore.kernel.org/netdev/20190129095754.9390-1-bjorn.topel@gmail.com/
and "The Path to DPDK Speeds for AF_XDP", LPC 2018, networking track:
- http://vger.kernel.org/lpc_net2018_talks/lpc18_pres_af_xdp_perf-v3.pdf
- http://vger.kernel.org/lpc_net2018_talks/lpc18_paper_af_xdp_perf-v2.pdf
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: netdev@vger.kernel.org Cc: David S. Miller <davem@davemloft.net> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20190221221941.29358-1-daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
A similar issue as fixed by Patch "tipc: check bearer name with right
length in tipc_nl_compat_bearer_enable" was also found by syzbot in
tipc_nl_compat_link_set().
The length to check with should be 'TLV_GET_DATA_LEN(msg->req) -
offsetof(struct tipc_link_config, name)'.
Reported-by: syzbot+de00a87b8644a582ae79@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Uninit was created at:
__alloc_skb+0x309/0xa20 net/core/skbuff.c:208
alloc_skb include/linux/skbuff.h:1012 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg net/socket.c:632 [inline]
It was triggered when the bearer name size < TIPC_MAX_BEARER_NAME,
it would check with a wrong len/TLV_GET_DATA_LEN(msg->req), which
also includes priority and disc_domain length.
This patch is to fix it by checking it with a right length:
'TLV_GET_DATA_LEN(msg->req) - offsetof(struct tipc_bearer_config, name)'.
Reported-by: syzbot+8b707430713eb46e1e45@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
syzbot is reporting uninitialized value at rpc_sockaddr2uaddr() [1]. This
is because syzbot is setting AF_INET6 to "struct sockaddr_in"->sin_family
(which is embedded into user-visible "struct nfs_mount_data" structure)
despite nfs23_validate_mount_data() cannot pass sizeof(struct sockaddr_in6)
bytes of AF_INET6 address to rpc_sockaddr2uaddr().
Since "struct nfs_mount_data" structure is user-visible, we can't change
"struct nfs_mount_data" to use "struct sockaddr_storage". Therefore,
assuming that everybody is using AF_INET family when passing address via
"struct nfs_mount_data"->addr, reject if its sin_family is not AF_INET.
[ ] WARNING: CPU: 4 PID: 17089 at kernel/sched/deadline.c:255 task_non_contending+0xae0/0x1950
line 255 of deadline.c is:
WARN_ON(hrtimer_active(&dl_se->inactive_timer));
in task_non_contending().
Unfortunately, in some cases (for example, a deadline task
continuosly blocking and waking immediately) it can happen that
a task blocks (and task_non_contending() is called) while the
0-lag timer is still active.
In this case, the safest thing to do is to immediately decrease
the running bandwidth of the task, without trying to re-arm the 0-lag timer.
Signed-off-by: luca abeni <luca.abeni@santannapisa.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: chengjian (D) <cj.chengjian@huawei.com> Link: https://lkml.kernel.org/r/20190325131530.34706-1-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
commit 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer
dereference in put_links") forgot to handle start_unregistering() case,
while header->parent is NULL, it calls erase_header() and as seen in the
above syzkaller call trace, accessing &header->parent->root will trigger
a NULL pointer dereference.
As that commit explained, there is also no need to call
start_unregistering() if header->parent is NULL.
Link: http://lkml.kernel.org/r/20190409153622.28112-1-yuehaibing@huawei.com Fixes: 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links") Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Commit 9ed3f22223c3 ("intel_th: Don't reference unassigned outputs")
fixes a NULL dereference for all masters except the last one ("256+"),
which keeps the stale pointer after the output driver had been unassigned.