Hello,
syzbot found the following crash on:
HEAD commit: 1f22d15c usb: gadget: add raw-gadget interface
git tree: https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=1296f42ae00000
kernel config: https://syzkaller.appspot.com/x/.config?x=8ccee2968018adcb
dashboard link: https://syzkaller.appspot.com/bug?extid=c7b0ec009a216143df30
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+c7b0ec009a216143df30@xxxxxxxxxxxxxxxxxxxxxxxxx
==================================================================
BUG: KASAN: use-after-free in __mutex_lock_common
kernel/locking/mutex.c:1043 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0x124d/0x1360
kernel/locking/mutex.c:1106
Read of size 8 at addr ffff8881cad4d8b8 by task v4l_id/4526
CPU: 0 PID: 4526 Comm: v4l_id Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xef/0x16e lib/dump_stack.c:118
print_address_description.constprop.0+0x36/0x50 mm/kasan/report.c:374
__kasan_report.cold+0x1a/0x33 mm/kasan/report.c:506
kasan_report+0xe/0x20 mm/kasan/common.c:638
__mutex_lock_common kernel/locking/mutex.c:1043 [inline]
__mutex_lock+0x124d/0x1360 kernel/locking/mutex.c:1106
usbvision_v4l2_open+0x77/0x340
drivers/media/usb/usbvision/usbvision-video.c:314
v4l2_open+0x20f/0x3d0 drivers/media/v4l2-core/v4l2-dev.c:423
chrdev_open+0x219/0x5c0 fs/char_dev.c:414
do_dentry_open+0x494/0x1120 fs/open.c:797
do_last fs/namei.c:3412 [inline]
path_openat+0x142b/0x4030 fs/namei.c:3529
do_filp_open+0x1a1/0x280 fs/namei.c:3559
do_sys_open+0x3c0/0x580 fs/open.c:1097
do_syscall_64+0xb7/0x5b0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f70d3cab120
Code: 48 8b 15 1b 4d 2b 00 f7 d8 64 89 02 83 c8 ff c3 90 90 90 90 90 90 90
90 90 90 83 3d d5 a4 2b 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 73 31 c3 48 83 ec 08 e8 5e 8c 01 00 48 89 04 24
RSP: 002b:00007ffc46d40ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007ffc46d40e08 RCX: 00007f70d3cab120
RDX: 00007f70d3f60138 RSI: 0000000000000000 RDI: 00007ffc46d42f1d
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400884
R13: 00007ffc46d40e00 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 12:
save_stack+0x1b/0x80 mm/kasan/common.c:71
set_track mm/kasan/common.c:79 [inline]
__kasan_kmalloc mm/kasan/common.c:512 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:485
kmalloc include/linux/slab.h:556 [inline]
kzalloc include/linux/slab.h:670 [inline]
usbvision_alloc drivers/media/usb/usbvision/usbvision-video.c:1315 [inline]
usbvision_probe.cold+0x5c5/0x1f1e
drivers/media/usb/usbvision/usbvision-video.c:1469
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0x1480/0x1c20 drivers/base/core.c:2487
usb_set_configuration+0xe67/0x1740 drivers/usb/core/message.c:2023
generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
really_probe+0x281/0x6d0 drivers/base/dd.c:548
driver_probe_device+0x104/0x210 drivers/base/dd.c:721
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x360 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0x1480/0x1c20 drivers/base/core.c:2487
usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537
hub_port_connect drivers/usb/core/hub.c:5184 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5324 [inline]
port_event drivers/usb/core/hub.c:5470 [inline]
hub_event+0x1e59/0x3860 drivers/usb/core/hub.c:5552
process_one_work+0x92b/0x1530 kernel/workqueue.c:2264
worker_thread+0x96/0xe20 kernel/workqueue.c:2410
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Freed by task 3310:
save_stack+0x1b/0x80 mm/kasan/common.c:71
set_track mm/kasan/common.c:79 [inline]
kasan_set_free_info mm/kasan/common.c:334 [inline]
__kasan_slab_free+0x130/0x180 mm/kasan/common.c:473
slab_free_hook mm/slub.c:1425 [inline]
slab_free_freelist_hook mm/slub.c:1458 [inline]
slab_free mm/slub.c:3005 [inline]
kfree+0xdc/0x310 mm/slub.c:3957
usbvision_release+0x181/0x1c0
drivers/media/usb/usbvision/usbvision-video.c:1364
usbvision_disconnect+0x171/0x1e0
drivers/media/usb/usbvision/usbvision-video.c:1589
usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423
__device_release_driver drivers/base/dd.c:1134 [inline]
device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1165
bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:532
device_del+0x481/0xd30 drivers/base/core.c:2664
usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
usb_disconnect+0x284/0x8d0 drivers/usb/core/hub.c:2200
hub_port_connect drivers/usb/core/hub.c:5035 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5324 [inline]
port_event drivers/usb/core/hub.c:5470 [inline]
hub_event+0x1753/0x3860 drivers/usb/core/hub.c:5552
process_one_work+0x92b/0x1530 kernel/workqueue.c:2264
worker_thread+0x96/0xe20 kernel/workqueue.c:2410
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
The buggy address belongs to the object at ffff8881cad4c000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6328 bytes inside of
8192-byte region [ffff8881cad4c000, ffff8881cad4e000)
The buggy address belongs to the page:
page:ffffea00072b5200 refcount:1 mapcount:0 mapping:ffff8881da40c500
index:0x0 compound_mapcount: 0
raw: 0200000000010200 ffffea0007249a00 0000000200000002 ffff8881da40c500
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881cad4d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881cad4d800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881cad4d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881cad4d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881cad4d980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This bug is generated by a bot. It may contain errors.
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