From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Pavel Skripkin paskripkin@gmail.com
commit 30dea07180de3aa0ad613af88431ef4e34b5ef68 upstream.
syzbot reported null pointer dereference in usb_audio_probe. The problem was in case, when quirk == NULL. It's not an error condition, so quirk must be checked before dereferencing.
Call Trace: usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396 really_probe+0x291/0xe60 drivers/base/dd.c:554 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:740 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:846 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x228/0x4a0 drivers/base/dd.c:914 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xbdb/0x1db0 drivers/base/core.c:3242 usb_set_configuration+0x113f/0x1910 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238 usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293 really_probe+0x291/0xe60 drivers/base/dd.c:554 driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:740 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:846 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x228/0x4a0 drivers/base/dd.c:914 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xbdb/0x1db0 drivers/base/core.c:3242 usb_new_device.cold+0x721/0x1058 drivers/usb/core/hub.c:2555 hub_port_connect drivers/usb/core/hub.c:5223 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x2357/0x4320 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Reported-by: syzbot+719da9b149a931f5143f@syzkaller.appspotmail.com Fixes: 9799110825db ("ALSA: usb-audio: Disable USB autosuspend properly in setup_disable_autosuspend()") Signed-off-by: Pavel Skripkin paskripkin@gmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/f1ebad6e721412843bd1b12584444c0a63c6b2fb.161524218... Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/usb/card.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -831,7 +831,8 @@ static int usb_audio_probe(struct usb_in snd_media_device_create(chip, intf); }
- chip->quirk_type = quirk->type; + if (quirk) + chip->quirk_type = quirk->type;
usb_chip[chip->index] = chip; chip->intf[chip->num_interfaces] = intf;