usb: typec: tcpm: Add NULL check before dereferencing config
When instantiating tcpm on an NXP OM 13588 board with NXP PTN5110,
the following crash is seen when writing into the 'preferred_role'
sysfs attribute.
Unable to handle kernel NULL pointer dereference at virtual address
00000028
pgd =
f69149ad
[
00000028] *pgd=
00000000
Internal error: Oops: 5 [#1] THUMB2
Modules linked in: tcpci tcpm
CPU: 0 PID: 1882 Comm: bash Not tainted 5.1.18-sama5-armv7-r2 #4
Hardware name: Atmel SAMA5
PC is at tcpm_try_role+0x3a/0x4c [tcpm]
LR is at tcpm_try_role+0x15/0x4c [tcpm]
pc : [<
bf8000e2>] lr : [<
bf8000bd>] psr:
60030033
sp :
dc1a1e88 ip :
c03fb47d fp :
00000000
r10:
dc216190 r9 :
dc1a1f78 r8 :
00000001
r7 :
df4ae044 r6 :
dd032e90 r5 :
dd1ce340 r4 :
df4ae054
r3 :
00000000 r2 :
00000000 r1 :
00000000 r0 :
df4ae044
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA Thumb Segment none
Control:
50c53c7d Table:
3efec059 DAC:
00000051
Process bash (pid: 1882, stack limit = 0x6a6d4aa5)
Stack: (0xdc1a1e88 to 0xdc1a2000)
1e80:
dd05d808 dd1ce340 00000001 00000007 dd1ce340 c03fb4a7
1ea0:
00000007 00000007 dc216180 00000000 00000000 c01e1e03 00000000 00000000
1ec0:
c0907008 dee98b40 c01e1d5d c06106c4 00000000 00000000 00000007 c0194e8b
1ee0:
0000000a 00000400 00000000 c01a97db dc22bf00 ffffe000 df4b6a00 df745900
1f00:
00000001 00000001 000000dd c01a9c2f 7aeab3be c0907008 00000000 dc22bf00
1f20:
c0907008 00000000 00000000 00000000 00000000 7aeab3be 00000007 dee98b40
1f40:
005dc318 dc1a1f78 00000000 00000000 00000007 c01969f7 0000000a c01a20cb
1f60:
dee98b40 c0907008 dee98b40 005dc318 00000000 c0196b9b 00000000 00000000
1f80:
dee98b40 7aeab3be 00000074 005dc318 b6f3bdb0 00000004 c0101224 dc1a0000
1fa0:
00000004 c0101001 00000074 005dc318 00000001 005dc318 00000007 00000000
1fc0:
00000074 005dc318 b6f3bdb0 00000004 00000007 00000007 00000000 00000000
1fe0:
00000004 be800880 b6ed35b3 b6e5c746 60030030 00000001 00000000 00000000
[<
bf8000e2>] (tcpm_try_role [tcpm]) from [<
c03fb4a7>] (preferred_role_store+0x2b/0x5c)
[<
c03fb4a7>] (preferred_role_store) from [<
c01e1e03>] (kernfs_fop_write+0xa7/0x150)
[<
c01e1e03>] (kernfs_fop_write) from [<
c0194e8b>] (__vfs_write+0x1f/0x104)
[<
c0194e8b>] (__vfs_write) from [<
c01969f7>] (vfs_write+0x6b/0x104)
[<
c01969f7>] (vfs_write) from [<
c0196b9b>] (ksys_write+0x43/0x94)
[<
c0196b9b>] (ksys_write) from [<
c0101001>] (ret_fast_syscall+0x1/0x62)
Since commit
96232cbc6c994 ("usb: typec: tcpm: support get typec and pd
config from device properties"), the 'config' pointer in struct tcpc_dev
is optional when registering a Type-C port. Since it is optional, we have
to check if it is NULL before dereferencing it.
Reported-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Fixes: 96232cbc6c994 ("usb: typec: tcpm: support get typec and pd config from device properties")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Jun Li <jun.li@nxp.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/1563979112-22483-1-git-send-email-linux@roeck-us.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>