Revert "media: dvb-core: Fix use-after-free on race condition at dvb_frontend"
As reported by Thomas Voegtle <tv@lio96.de>, sometimes a DVB card does
not initialize properly booting Linux 6.4-rc4. This is not always, maybe
in 3 out of 4 attempts.
After double-checking, the root cause seems to be related to the
UAF fix, which is causing a race issue:
[ 26.332149] tda10071 7-0005: found a 'NXP TDA10071' in cold state, will try to load a firmware
[ 26.340779] tda10071 7-0005: downloading firmware from file 'dvb-fe-tda10071.fw'
[ 989.277402] INFO: task vdr:743 blocked for more than 491 seconds.
[ 989.283504] Not tainted 6.4.0-rc5-i5 #249
[ 989.288036] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 989.295860] task:vdr state:D stack:0 pid:743 ppid:711 flags:0x00004002
[ 989.295865] Call Trace:
[ 989.295867] <TASK>
[ 989.295869] __schedule+0x2ea/0x12d0
[ 989.295877] ? asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 989.295881] schedule+0x57/0xc0
[ 989.295884] schedule_preempt_disabled+0xc/0x20
[ 989.295887] __mutex_lock.isra.16+0x237/0x480
[ 989.295891] ? dvb_get_property.isra.10+0x1bc/0xa50
[ 989.295898] ? dvb_frontend_stop+0x36/0x180
[ 989.338777] dvb_frontend_stop+0x36/0x180
[ 989.338781] dvb_frontend_open+0x2f1/0x470
[ 989.338784] dvb_device_open+0x81/0xf0
[ 989.338804] ? exact_lock+0x20/0x20
[ 989.338808] chrdev_open+0x7f/0x1c0
[ 989.338811] ? generic_permission+0x1a2/0x230
[ 989.338813] ? link_path_walk.part.63+0x340/0x380
[ 989.338815] ? exact_lock+0x20/0x20
[ 989.338817] do_dentry_open+0x18e/0x450
[ 989.374030] path_openat+0xca5/0xe00
[ 989.374031] ? terminate_walk+0xec/0x100
[ 989.374034] ? path_lookupat+0x93/0x140
[ 989.374036] do_filp_open+0xc0/0x140
[ 989.374038] ? __call_rcu_common.constprop.91+0x92/0x240
[ 989.374041] ? __check_object_size+0x147/0x260
[ 989.374043] ? __check_object_size+0x147/0x260
[ 989.374045] ? alloc_fd+0xbb/0x180
[ 989.374048] ? do_sys_openat2+0x243/0x310
[ 989.374050] do_sys_openat2+0x243/0x310
[ 989.374052] do_sys_open+0x52/0x80
[ 989.374055] do_syscall_64+0x5b/0x80
[ 989.421335] ? __task_pid_nr_ns+0x92/0xa0
[ 989.421337] ? syscall_exit_to_user_mode+0x20/0x40
[ 989.421339] ? do_syscall_64+0x67/0x80
[ 989.421341] ? syscall_exit_to_user_mode+0x20/0x40
[ 989.421343] ? do_syscall_64+0x67/0x80
[ 989.421345] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 989.421348] RIP: 0033:0x7fe895d067e3
[ 989.421349] RSP: 002b:
00007fff933c2ba0 EFLAGS:
00000293 ORIG_RAX:
0000000000000101
[ 989.421351] RAX:
ffffffffffffffda RBX:
00007fff933c2c10 RCX:
00007fe895d067e3
[ 989.421352] RDX:
0000000000000802 RSI:
00005594acdce160 RDI:
00000000ffffff9c
[ 989.421353] RBP:
0000000000000802 R08:
0000000000000000 R09:
0000000000000000
[ 989.421353] R10:
0000000000000000 R11:
0000000000000293 R12:
0000000000000001
[ 989.421354] R13:
00007fff933c2ca0 R14:
00000000ffffffff R15:
00007fff933c2c90
[ 989.421355] </TASK>
This reverts commit
6769a0b7ee0c3b31e1b22c3fadff2bfb642de23f.
Fixes: 6769a0b7ee0c ("media: dvb-core: Fix use-after-free on race condition at dvb_frontend")
Link: https://lore.kernel.org/all/da5382ad-09d6-20ac-0d53-611594b30861@lio96.de/
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>