kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-10 20:48:12 +00:00
Code Issues Releases Packages Activity

USB: serial: fix ioctl hangup race

Browse source 
The tty ioctls can race with hangup and end up calling into a tty driver
for a device that is already gone or powered down.

Serialise the callbacks using the tty port mutex and add the missing
checks to make sure the port has not been hung up before accessing port
driver data or hardware.

This specifically avoids dereferencing a NULL-pointer if a device is
disconnected during lengthy break signalling.

Note that TIOCGICOUNT and TIOCMIWAIT do not access port driver data or
hardware and are therefore not affected by the race.

Fixes: f34d7a5b70 ("tty: The big operations rework")
Reported-by: Nick Bowler <nbowler@draconx.ca>
Link: https://lore.kernel.org/all/CADyTPExB2kYOOwkO0JqGhKaYVDqO9uS9WCw0J=MCTdVhcGOogA@mail.gmail.com/
Reported-by: syzbot+473d7477c523b41d4046@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/6a9087a4.4d659fcc.734b4.0013.GAE@google.com
Cc: stable@vger.kernel.org	# 2.6.26
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2026-09-03 18:31:46 +02:00
commit ae0e61d956
3 changed files with 86 additions and 28 deletions
Download patch file Download diff file Expand all files Collapse all files