diff options
| author | Gautam Menghani <gautammenghani201@gmail.com> | 2022-10-19 06:02:14 +0100 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@kernel.org> | 2022-11-25 08:00:45 +0000 |
| commit | 813ceef062b53d68f296aa3cb944b21a091fabdb (patch) | |
| tree | b44f241888a1f804dfe8a68d8b8460ed394ab573 /drivers/media/rc | |
| parent | a42f363e6b58d1fc642d6d082dc660be73656ba5 (diff) | |
| download | linux-813ceef062b53d68f296aa3cb944b21a091fabdb.tar.bz2 | |
media: imon: fix a race condition in send_packet()
The function send_packet() has a race condition as follows:
func send_packet()
{
// do work
call usb_submit_urb()
mutex_unlock()
wait_for_event_interruptible() <-- lock gone
mutex_lock()
}
func vfd_write()
{
mutex_lock()
call send_packet() <- prev call is not completed
mutex_unlock()
}
When the mutex is unlocked and the function send_packet() waits for the
call to complete, vfd_write() can start another call, which leads to the
"URB submitted while active" warning in usb_submit_urb().
Fix this by removing the mutex_unlock() call in send_packet() and using
mutex_lock_interruptible().
Link: https://syzkaller.appspot.com/bug?id=e378e6a51fbe6c5cc43e34f131cc9a315ef0337e
Fixes: 21677cfc562a ("V4L/DVB: ir-core: add imon driver")
Reported-by: syzbot+0c3cb6dc05fbbdc3ad66@syzkaller.appspotmail.com
Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Diffstat (limited to 'drivers/media/rc')
| -rw-r--r-- | drivers/media/rc/imon.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c index 5edfd8a9e849..74546f7e3469 100644 --- a/drivers/media/rc/imon.c +++ b/drivers/media/rc/imon.c @@ -646,15 +646,14 @@ static int send_packet(struct imon_context *ictx) pr_err_ratelimited("error submitting urb(%d)\n", retval); } else { /* Wait for transmission to complete (or abort) */ - mutex_unlock(&ictx->lock); retval = wait_for_completion_interruptible( &ictx->tx.finished); if (retval) { usb_kill_urb(ictx->tx_urb); pr_err_ratelimited("task interrupted\n"); } - mutex_lock(&ictx->lock); + ictx->tx.busy = false; retval = ictx->tx.status; if (retval) pr_err_ratelimited("packet tx failed (%d)\n", retval); @@ -953,7 +952,8 @@ static ssize_t vfd_write(struct file *file, const char __user *buf, if (ictx->disconnected) return -ENODEV; - mutex_lock(&ictx->lock); + if (mutex_lock_interruptible(&ictx->lock)) + return -ERESTARTSYS; if (!ictx->dev_present_intf0) { pr_err_ratelimited("no iMON device present\n"); |