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authorMauro Carvalho Chehab <mchehab@kernel.org>2023-06-09 11:16:21 +0300
committerMauro Carvalho Chehab <mchehab@kernel.org>2023-06-15 01:16:29 +0300
commitec21a38df77a5aefbd2f70c48127003b6f259cf3 (patch)
tree4b377398be4bcd16fa9636b8f4a863afc98e8c5e /include/media
parent4b0a5014ee2b0984f2410d657dc582a8387585ae (diff)
downloadlinux-ec21a38df77a5aefbd2f70c48127003b6f259cf3.tar.xz
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>
Diffstat (limited to 'include/media')
-rw-r--r--include/media/dvb_frontend.h6
1 files changed, 1 insertions, 5 deletions
diff --git a/include/media/dvb_frontend.h b/include/media/dvb_frontend.h
index 367d5381217b..e7c44870f20d 100644
--- a/include/media/dvb_frontend.h
+++ b/include/media/dvb_frontend.h
@@ -686,10 +686,7 @@ struct dtv_frontend_properties {
* @id: Frontend ID
* @exit: Used to inform the DVB core that the frontend
* thread should exit (usually, means that the hardware
- * got disconnected).
- * @remove_mutex: mutex that avoids a race condition between a callback
- * called when the hardware is disconnected and the
- * file_operations of dvb_frontend.
+ * got disconnected.
*/
struct dvb_frontend {
@@ -707,7 +704,6 @@ struct dvb_frontend {
int (*callback)(void *adapter_priv, int component, int cmd, int arg);
int id;
unsigned int exit;
- struct mutex remove_mutex;
};
/**