tty: abort break signalling on hangup

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

Drivers must handle this race, but TCSBRK and TCSBRKP should still be
aborted to avoid calling back into the driver after a user-controlled
timeout (possibly even after the tty has been reopened).

Note that drivers should disable any break state on shutdown so just
return on hangup (calling break_ctl() again is racy and will most likely
fail for drivers handling the race).

Fixes: f34d7a5b70 ("tty: The big operations rework")
Cc: stable <stable@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260903163736.1499280-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2026-09-03 18:37:36 +02:00 • committed by Greg Kroah-Hartman
commit 845a2737e0
2 changed files with 28 additions and 9 deletions