[ Upstream commit 24147897507cd3a7d63745d1518a638bf4132238 ]
Lets fix a race between mutex_is_lock() and mutex_lock().
<-mutex is not locked
if (!mutex_is_locked(&ictx->lock)) {
unlock = true; <- mutex is locked externaly
mutex_lock(&ictx->lock);
}
Let's use mutex_trylock() that does mutex_is_lock() and mutex_lock()
atomically.
Fix the following cocci warning:
drivers/media/rc/imon.c:1167:1-7: preceding lock on line 1153
Fixes: 23ef710e1a6c ("[media] imon: add conditional locking in change_protocol")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a1766a4fd83befa0b34d932d532e7ebb7fab1fa7 ]
imon driver probes two USB interfaces, and at the probe of the second
interface, the driver assumes blindly that the first interface got
bound with the same imon driver. It's usually true, but it's still
possible that the first interface is bound with another driver via a
malformed descriptor. Then it may lead to a memory corruption, as
spotted by syzkaller; imon driver accesses the data from drvdata as
struct imon_context object although it's a completely different one
that was assigned by another driver.
This patch adds a sanity check -- whether the first interface is
really bound with the imon driver or not -- for avoiding the problem
above at the probe time.
Reported-by: syzbot+59875ffef5cb9c9b29e9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000a838aa0603cc74d6@google.com/
Tested-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20230922005152.163640-1-ricardo@marliere.net
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
