diff options
| author | Johan Hovold <johan@kernel.org> | 2019-09-19 10:30:37 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-17 13:41:02 -0700 |
| commit | 2e0bcd20f6c72a0ca0aae5ccd6125e20a95abac4 (patch) | |
| tree | dc1939b2bdfaf06db2678a42f446fde6887c381c /kernel/trace/trace_functions_graph.c | |
| parent | ce29fc8d82972c9f8621c2063adffac6a342bbff (diff) | |
USB: legousbtower: fix deadlock on disconnect
commit 33a7813219f208f4952ece60ee255fd983272dec upstream.
Fix a potential deadlock if disconnect races with open.
Since commit d4ead16f50f9 ("USB: prevent char device open/deregister
race") core holds an rw-semaphore while open is called and when
releasing the minor number during deregistration. This can lead to an
ABBA deadlock if a driver takes a lock in open which it also holds
during deregistration.
This effectively reverts commit 78663ecc344b ("USB: disconnect open race
in legousbtower") which needlessly introduced this issue after a generic
fix for this race had been added to core by commit d4ead16f50f9 ("USB:
prevent char device open/deregister race").
Fixes: 78663ecc344b ("USB: disconnect open race in legousbtower")
Cc: stable <stable@vger.kernel.org> # 2.6.24
Reported-by: syzbot+f9549f5ee8a5416f0b95@syzkaller.appspotmail.com
Tested-by: syzbot+f9549f5ee8a5416f0b95@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190919083039.30898-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
0 files changed, 0 insertions, 0 deletions