syzbot has found a reproducer for the following crash on:
HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver
git tree: https://github.com/google/kasan/tree/usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=1364598f200000
kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15
dashboard link: https://syzkaller.appspot.com/bug?extid=a4387f5b6b799f6becbf
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1165b9b7200000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13b224cb200000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a4387f5b6b799f6becbf@xxxxxxxxxxxxxxxxxxxxxxxxx
radio-raremono 3-1:0.210: Thanko's Raremono disconnected
radio-raremono 6-1:0.210: Thanko's Raremono disconnected
radio-raremono 2-1:0.210: Thanko's Raremono disconnected
usb 5-1: new high-speed USB device number 92 using dummy_hcd
==================================================================
BUG: KASAN: use-after-free in v4l2_release+0x322/0x390
drivers/media/v4l2-core/v4l2-dev.c:453
Read of size 8 at addr ffff888098dca3e0 by task v4l_id/7099
CPU: 0 PID: 7099 Comm: v4l_id Not tainted 5.1.0-rc4-319354-g9a33b36 #3
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+0xe8/0x16e lib/dump_stack.c:113
print_address_description+0x6c/0x236 mm/kasan/report.c:187
kasan_report.cold+0x1a/0x3c mm/kasan/report.c:317
v4l2_release+0x322/0x390 drivers/media/v4l2-core/v4l2-dev.c:453
__fput+0x2df/0x8c0 fs/file_table.c:278
task_work_run+0x149/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x243/0x270 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
do_syscall_64+0x40c/0x4f0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fa9f8fc12b0
Code: 40 75 0b 31 c0 48 83 c4 08 e9 0c ff ff ff 48 8d 3d c5 32 08 00 e8 c0
07 02 00 83 3d 45 a3 2b 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 73 31 c3 48 83 ec 08 e8 ce 8a 01 00 48 89 04 24
RSP: 002b:00007ffd121e3378 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fa9f8fc12b0
RDX: 00007fa9f9277df0 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fa9f9277df0 R09: 000000000000000a
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400884
R13: 00007ffd121e34d0 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 5386:
set_track mm/kasan/common.c:87 [inline]
__kasan_kmalloc mm/kasan/common.c:497 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:470
slab_post_alloc_hook mm/slab.h:437 [inline]
slab_alloc_node mm/slub.c:2756 [inline]
__kmalloc_node_track_caller+0xf3/0x320 mm/slub.c:4372
alloc_dr drivers/base/devres.c:103 [inline]
devm_kmalloc+0x8c/0x190 drivers/base/devres.c:793
devm_kzalloc include/linux/device.h:679 [inline]
usb_raremono_probe+0x34/0x235 drivers/media/radio/radio-raremono.c:298
usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
really_probe+0x2da/0xb10 drivers/base/dd.c:509
driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
__device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
__device_attach+0x223/0x3a0 drivers/base/dd.c:844
bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
device_add+0xad2/0x16e0 drivers/base/core.c:2106
usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
really_probe+0x2da/0xb10 drivers/base/dd.c:509
driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
__device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
__device_attach+0x223/0x3a0 drivers/base/dd.c:844
bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
device_add+0xad2/0x16e0 drivers/base/core.c:2106
usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
hub_port_connect drivers/usb/core/hub.c:5089 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
port_event drivers/usb/core/hub.c:5350 [inline]
hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
process_scheduled_works kernel/workqueue.c:2331 [inline]
worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417
kthread+0x313/0x420 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Freed by task 5386:
set_track mm/kasan/common.c:87 [inline]
__kasan_slab_free+0x130/0x180 mm/kasan/common.c:459
slab_free_hook mm/slub.c:1429 [inline]
slab_free_freelist_hook+0x5e/0x140 mm/slub.c:1456
slab_free mm/slub.c:3003 [inline]
kfree+0xce/0x290 mm/slub.c:3958
release_nodes+0x4ac/0x920 drivers/base/devres.c:508
devres_release_all+0x79/0xc8 drivers/base/devres.c:529
__device_release_driver drivers/base/dd.c:1086 [inline]
device_release_driver_internal+0x23a/0x4f0 drivers/base/dd.c:1113
bus_remove_device+0x302/0x5c0 drivers/base/bus.c:556
device_del+0x467/0xb90 drivers/base/core.c:2269
usb_disable_device+0x242/0x790 drivers/usb/core/message.c:1235
usb_disconnect+0x298/0x870 drivers/usb/core/hub.c:2197
hub_port_connect drivers/usb/core/hub.c:4940 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
port_event drivers/usb/core/hub.c:5350 [inline]
hub_event+0xcd2/0x3b00 drivers/usb/core/hub.c:5432
process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
process_scheduled_works kernel/workqueue.c:2331 [inline]
worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417
kthread+0x313/0x420 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
The buggy address belongs to the object at ffff888098dca200
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 480 bytes inside of
4096-byte region [ffff888098dca200, ffff888098dcb200)
The buggy address belongs to the page:
page:ffffea0002637200 count:1 mapcount:0 mapping:ffff88812c3f4600
index:0xffff888098dcb300 compound_mapcount: 0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 ffffea0002638008 ffffea0002477808 ffff88812c3f4600
raw: ffff888098dcb300 0000000000070006 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888098dca280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888098dca300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888098dca380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888098dca400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888098dca480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
