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| author | Takashi Iwai <tiwai@suse.de> | 2025-05-19 23:20:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-12 12:56:21 +0200 |
| commit | 647410a7da46067953a53c0d03f8680eff570959 (patch) | |
| tree | 51f26d6356e3745523eddea7849b2d4280d4d507 | |
| parent | 97e87f367c911b1d7971eb062989d12123702f82 (diff) | |
| download | linux-647410a7da46067953a53c0d03f8680eff570959.tar.gz linux-647410a7da46067953a53c0d03f8680eff570959.tar.bz2 linux-647410a7da46067953a53c0d03f8680eff570959.zip | |
ALSA: usb-audio: Kill timer properly at removal
commit 0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1 upstream.
The USB-audio MIDI code initializes the timer, but in a rare case, the
driver might be freed without the disconnect call. This leaves the
timer in an active state while the assigned object is released via
snd_usbmidi_free(), which ends up with a kernel warning when the debug
configuration is enabled, as spotted by fuzzer.
For avoiding the problem, put timer_shutdown_sync() at
snd_usbmidi_free(), so that the timer can be killed properly.
While we're at it, replace the existing timer_delete_sync() at the
disconnect callback with timer_shutdown_sync(), too.
Reported-by: syzbot+d8f72178ab6783a7daea@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/681c70d7.050a0220.a19a9.00c6.GAE@google.com
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20250519212031.14436-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[ del_timer vs timer_delete differences ]
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | sound/usb/midi.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sound/usb/midi.c b/sound/usb/midi.c index 3059f814eb5c..cfebb223cf3e 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1530,6 +1530,7 @@ static void snd_usbmidi_free(struct snd_usb_midi *umidi) snd_usbmidi_in_endpoint_delete(ep->in); } mutex_destroy(&umidi->mutex); + timer_shutdown_sync(&umidi->error_timer); kfree(umidi); } @@ -1553,7 +1554,7 @@ void snd_usbmidi_disconnect(struct list_head *p) spin_unlock_irq(&umidi->disc_lock); up_write(&umidi->disc_rwsem); - del_timer_sync(&umidi->error_timer); + timer_shutdown_sync(&umidi->error_timer); for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) { struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i]; |