Hello,
syzbot found the following crash on:
HEAD commit: ae179410 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=132aa915e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=57adcee0a60380e2
dashboard link: https://syzkaller.appspot.com/bug?extid=75287f75e2fedd69d680
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: [email protected]
usbvision_radio_close: Final disconnect
==================================================================
BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390
drivers/media/v4l2-core/v4l2-dev.c:459
Read of size 4 at addr ffff8881d13b5068 by task v4l_id/20136
CPU: 1 PID: 20136 Comm: v4l_id Not tainted 5.5.0-rc3-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+0x16/0x200 mm/kasan/report.c:374
__kasan_report.cold+0x37/0x7f mm/kasan/report.c:506
kasan_report+0xe/0x20 mm/kasan/common.c:639
v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
__fput+0x2d7/0x840 fs/file_table.c:280
task_work_run+0x13f/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
do_syscall_64+0x4e0/0x5c0 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f70446a32b0
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:00007ffee1722fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f70446a32b0
RDX: 0000000000000013 RSI: 0000000080685600 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400884
R13: 00007ffee1723130 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 14633:
save_stack+0x1b/0x80 mm/kasan/common.c:72
set_track mm/kasan/common.c:80 [inline]
__kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:486
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+0x5c5/0x1f21
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+0x141f/0x1bc0 drivers/base/core.c:2487
usb_set_configuration+0xe38/0x16c0 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+0x141f/0x1bc0 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
process_scheduled_works kernel/workqueue.c:2326 [inline]
worker_thread+0x7ab/0xe20 kernel/workqueue.c:2412
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Freed by task 20136:
save_stack+0x1b/0x80 mm/kasan/common.c:72
set_track mm/kasan/common.c:80 [inline]
kasan_set_free_info mm/kasan/common.c:335 [inline]
__kasan_slab_free+0x129/0x170 mm/kasan/common.c:474
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+0xda/0x310 mm/slub.c:3957
usbvision_release+0x181/0x1c0
drivers/media/usb/usbvision/usbvision-video.c:1364
usbvision_radio_close.cold+0x2b/0x74
drivers/media/usb/usbvision/usbvision-video.c:1130
v4l2_release+0x2e7/0x390 drivers/media/v4l2-core/v4l2-dev.c:455
__fput+0x2d7/0x840 fs/file_table.c:280
task_work_run+0x13f/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
do_syscall_64+0x4e0/0x5c0 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8881d13b4000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4200 bytes inside of
8192-byte region [ffff8881d13b4000, ffff8881d13b6000)
The buggy address belongs to the page:
page:ffffea000744ec00 refcount:1 mapcount:0 mapping:ffff8881da40c500
index:0x0 compound_mapcount: 0
raw: 0200000000010200 ffffea0007392a00 0000000300000003 ffff8881da40c500
raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881d13b4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d13b4f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8881d13b5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881d13b5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881d13b5100: 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.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot has found a reproducer for the following crash on:
HEAD commit: 4cc301ee 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=17f5a721e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9ba75825443d54bd
dashboard link: https://syzkaller.appspot.com/bug?extid=75287f75e2fedd69d680
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16a0b6f1e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1327dd76e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email protected]
usbvision_set_audio: can't write iopin register for audio switching
usbvision_radio_close: Final disconnect
==================================================================
BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
Read of size 4 at addr ffff8881caba1068 by task v4l_id/1913
CPU: 1 PID: 1913 Comm: v4l_id Not tainted 5.5.0-rc6-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.cold+0xd3/0x314 mm/kasan/report.c:374
__kasan_report.cold+0x37/0x85 mm/kasan/report.c:506
kasan_report+0xe/0x20 mm/kasan/common.c:639
v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
__fput+0x2d7/0x840 fs/file_table.c:280
task_work_run+0x13f/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fbeb0b822b0
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:00007ffe52d6b158 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fbeb0b822b0
RDX: 0000000000000013 RSI: 0000000080685600 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400884
R13: 00007ffe52d6b2b0 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 94:
save_stack+0x1b/0x80 mm/kasan/common.c:72
set_track mm/kasan/common.c:80 [inline]
__kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:486
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+0x5c5/0x1f21 drivers/media/usb/usbvision/usbvision-video.c:1469
usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:361
really_probe+0x290/0xad0 drivers/base/dd.c:548
driver_probe_device+0x223/0x350 drivers/base/dd.c:721
__device_attach_driver+0x1d1/0x290 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x390 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0x1459/0x1bf0 drivers/base/core.c:2487
usb_set_configuration+0xe47/0x17d0 drivers/usb/core/message.c:2023
generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
usb_probe_device+0xaf/0x140 drivers/usb/core/driver.c:266
really_probe+0x290/0xad0 drivers/base/dd.c:548
driver_probe_device+0x223/0x350 drivers/base/dd.c:721
__device_attach_driver+0x1d1/0x290 drivers/base/dd.c:828
bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
__device_attach+0x217/0x390 drivers/base/dd.c:894
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
device_add+0x1459/0x1bf0 drivers/base/core.c:2487
usb_new_device.cold+0x540/0xcd0 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+0x21cb/0x4300 drivers/usb/core/hub.c:5552
process_one_work+0x945/0x15c0 kernel/workqueue.c:2264
process_scheduled_works kernel/workqueue.c:2326 [inline]
worker_thread+0x7ab/0xe20 kernel/workqueue.c:2412
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Freed by task 1913:
save_stack+0x1b/0x80 mm/kasan/common.c:72
set_track mm/kasan/common.c:80 [inline]
kasan_set_free_info mm/kasan/common.c:335 [inline]
__kasan_slab_free+0x117/0x160 mm/kasan/common.c:474
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+0xd5/0x300 mm/slub.c:3957
usbvision_release+0x181/0x1c0 drivers/media/usb/usbvision/usbvision-video.c:1364
usbvision_radio_close.cold+0x2b/0x74 drivers/media/usb/usbvision/usbvision-video.c:1130
v4l2_release+0x2e7/0x390 drivers/media/v4l2-core/v4l2-dev.c:455
__fput+0x2d7/0x840 fs/file_table.c:280
task_work_run+0x13f/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8881caba0000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4200 bytes inside of
8192-byte region [ffff8881caba0000, ffff8881caba2000)
The buggy address belongs to the page:
page:ffffea00072ae800 refcount:1 mapcount:0 mapping:ffff8881da00c500 index:0x0 compound_mapcount: 0
raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da00c500
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881caba0f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881caba0f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881caba1000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881caba1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881caba1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Hi Hillf,
On Thu, Jan 23, 2020 at 06:27:07PM +0800, Hillf Danton wrote:
> Wed, 22 Jan 2020 14:58:08 -0800 (PST)
> > syzbot has found a reproducer for the following crash on:
> >
> > HEAD commit: 4cc301ee 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=17f5a721e00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=9ba75825443d54bd
> > dashboard link: https://syzkaller.appspot.com/bug?extid=75287f75e2fedd69d680
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16a0b6f1e00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1327dd76e00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: [email protected]
> >
> > usbvision_set_audio: can't write iopin register for audio switching
> > usbvision_radio_close: Final disconnect
> > ==================================================================
> > BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
> > Read of size 4 at addr ffff8881caba1068 by task v4l_id/1913
> >
> > CPU: 1 PID: 1913 Comm: v4l_id Not tainted 5.5.0-rc6-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.cold+0xd3/0x314 mm/kasan/report.c:374
> > __kasan_report.cold+0x37/0x85 mm/kasan/report.c:506
> > kasan_report+0xe/0x20 mm/kasan/common.c:639
> > v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
> > __fput+0x2d7/0x840 fs/file_table.c:280
> > task_work_run+0x13f/0x1c0 kernel/task_work.c:113
> > tracehook_notify_resume include/linux/tracehook.h:188 [inline]
> > exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:164
> > prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
> > syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
> > do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304
> > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > RIP: 0033:0x7fbeb0b822b0
> > 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:00007ffe52d6b158 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
> > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fbeb0b822b0
> > RDX: 0000000000000013 RSI: 0000000080685600 RDI: 0000000000000003
> > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400884
> > R13: 00007ffe52d6b2b0 R14: 0000000000000000 R15: 0000000000000000
> >
> > Allocated by task 94:
> > save_stack+0x1b/0x80 mm/kasan/common.c:72
> > set_track mm/kasan/common.c:80 [inline]
> > __kasan_kmalloc mm/kasan/common.c:513 [inline]
> > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:486
> > 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+0x5c5/0x1f21 drivers/media/usb/usbvision/usbvision-video.c:1469
> > usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:361
> > really_probe+0x290/0xad0 drivers/base/dd.c:548
> > driver_probe_device+0x223/0x350 drivers/base/dd.c:721
> > __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:828
> > bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
> > __device_attach+0x217/0x390 drivers/base/dd.c:894
> > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
> > device_add+0x1459/0x1bf0 drivers/base/core.c:2487
> > usb_set_configuration+0xe47/0x17d0 drivers/usb/core/message.c:2023
> > generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
> > usb_probe_device+0xaf/0x140 drivers/usb/core/driver.c:266
> > really_probe+0x290/0xad0 drivers/base/dd.c:548
> > driver_probe_device+0x223/0x350 drivers/base/dd.c:721
> > __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:828
> > bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
> > __device_attach+0x217/0x390 drivers/base/dd.c:894
> > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
> > device_add+0x1459/0x1bf0 drivers/base/core.c:2487
> > usb_new_device.cold+0x540/0xcd0 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+0x21cb/0x4300 drivers/usb/core/hub.c:5552
> > process_one_work+0x945/0x15c0 kernel/workqueue.c:2264
> > process_scheduled_works kernel/workqueue.c:2326 [inline]
> > worker_thread+0x7ab/0xe20 kernel/workqueue.c:2412
> > kthread+0x318/0x420 kernel/kthread.c:255
> > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> >
> > Freed by task 1913:
> > save_stack+0x1b/0x80 mm/kasan/common.c:72
> > set_track mm/kasan/common.c:80 [inline]
> > kasan_set_free_info mm/kasan/common.c:335 [inline]
> > __kasan_slab_free+0x117/0x160 mm/kasan/common.c:474
> > 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+0xd5/0x300 mm/slub.c:3957
> > usbvision_release+0x181/0x1c0 drivers/media/usb/usbvision/usbvision-video.c:1364
> > usbvision_radio_close.cold+0x2b/0x74 drivers/media/usb/usbvision/usbvision-video.c:1130
> > v4l2_release+0x2e7/0x390 drivers/media/v4l2-core/v4l2-dev.c:455
> > __fput+0x2d7/0x840 fs/file_table.c:280
> > task_work_run+0x13f/0x1c0 kernel/task_work.c:113
> > tracehook_notify_resume include/linux/tracehook.h:188 [inline]
> > exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:164
> > prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
> > syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
> > do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304
> > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> >
> > The buggy address belongs to the object at ffff8881caba0000
> > which belongs to the cache kmalloc-8k of size 8192
> > The buggy address is located 4200 bytes inside of
> > 8192-byte region [ffff8881caba0000, ffff8881caba2000)
> > The buggy address belongs to the page:
> > page:ffffea00072ae800 refcount:1 mapcount:0 mapping:ffff8881da00c500 index:0x0 compound_mapcount: 0
> > raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da00c500
> > raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
> > page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> > ffff8881caba0f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8881caba0f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > >ffff8881caba1000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ^
> > ffff8881caba1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8881caba1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ==================================================================
>
>
> Add the release callback for usbvision video device and use it to release
> resources when the last reference to the device goes away.
Would you be able to submit this with a commit message and your
Signed-off-by line ?
> --- a/drivers/media/usb/usbvision/usbvision-video.c
> +++ b/drivers/media/usb/usbvision/usbvision-video.c
> @@ -401,7 +401,6 @@ static int usbvision_v4l2_close(struct f
>
> if (r) {
> printk(KERN_INFO "%s: Final disconnect\n", __func__);
> - usbvision_release(usbvision);
> return 0;
> }
>
> @@ -409,6 +408,11 @@ static int usbvision_v4l2_close(struct f
> return v4l2_fh_release(file);
> }
>
> +static void usbvision_video_device_release(struct video_device *vdev)
> +{
> + struct usb_usbvision *usbvision = video_get_drvdata(vdev);
> + usbvision_release(usbvision);
> +}
>
> /*
> * usbvision_ioctl()
> @@ -1181,7 +1185,7 @@ static struct video_device usbvision_vid
> .fops = &usbvision_fops,
> .ioctl_ops = &usbvision_ioctl_ops,
> .name = "usbvision-video",
> - .release = video_device_release_empty,
> + .release = usbvision_video_device_release,
> .tvnorms = USBVISION_NORMS,
> };
>
> --- a/drivers/media/v4l2-core/v4l2-dev.c
> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> @@ -206,7 +206,10 @@ static void v4l2_device_release(struct d
> }
> #endif
>
> - /* Do not call v4l2_device_put if there is no release callback set.
> + /*
> + * Decrease v4l2_device refcount
> + *
> + * Do not call v4l2_device_put if there is no release callback set.
> * Drivers that have no v4l2_device release callback might free the
> * v4l2_dev instance in the video_device release callback below, so we
> * must perform this check here.
> @@ -214,16 +217,12 @@ static void v4l2_device_release(struct d
> * TODO: In the long run all drivers that use v4l2_device should use the
> * v4l2_device release callback. This check will then be unnecessary.
> */
> - if (v4l2_dev->release == NULL)
> - v4l2_dev = NULL;
> + if (v4l2_dev->release)
> + v4l2_device_put(v4l2_dev);
>
> /* Release video_device and perform other
> cleanups as needed. */
> vdev->release(vdev);
> -
> - /* Decrease v4l2_device refcount */
> - if (v4l2_dev)
> - v4l2_device_put(v4l2_dev);
> }
>
> static struct class video_class = {
--
Regards,
Laurent Pinchart
On Fri, Jan 24, 2020 at 3:29 AM Hillf Danton <[email protected]> wrote:
>
>
> On Thu, 23 Jan 2020 14:19:47 +0200 Laurent Pinchart wrote:
> > On Thu, Jan 23, 2020 at 06:27:07PM +0800, Hillf Danton wrote:
> > > Wed, 22 Jan 2020 14:58:08 -0800 (PST)
> > > > syzbot has found a reproducer for the following crash on:
> > > >
> > > > HEAD commit: 4cc301ee 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=17f5a721e00000
> > > > kernel config: https://syzkaller.appspot.com/x/.config?x=9ba75825443d54bd
> > > > dashboard link: https://syzkaller.appspot.com/bug?extid=75287f75e2fedd69d680
> > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16a0b6f1e00000
> > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1327dd76e00000
> > > >
> > > > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > > > Reported-by: [email protected]
> > > >
> > > > usbvision_set_audio: can't write iopin register for audio switching
> > > > usbvision_radio_close: Final disconnect
> > > > ==================================================================
> > > > BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
> > > > Read of size 4 at addr ffff8881caba1068 by task v4l_id/1913
>
> <snip>
>
> > > Add the release callback for usbvision video device and use it to release
> > > resources when the last reference to the device goes away.
> >
> > Would you be able to submit this with a commit message and your
> > Signed-off-by line ?
>
> ---8<---
> Subject: [PATCH] media: usbvision: add the release callback for video device
> From: Hillf Danton <[email protected]>
>
> To fix the UAF syzbot reported,
>
> BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
>
> a release cb which is a simple wrapper of usbvision_release() is added
> for releasing resources as the last reference to the usbvision video
> device goes away.
>
> Reported-by: syzbot <[email protected]>
> Fixes: 2aa689dd8057 ("[media] usbvision: embed video_device")
> Cc: Hans Verkuil <[email protected]>
> Signed-off-by: Hillf Danton <[email protected]>
> ---
>
> --- a/drivers/media/usb/usbvision/usbvision-video.c
> +++ b/drivers/media/usb/usbvision/usbvision-video.c
> @@ -401,7 +401,6 @@ static int usbvision_v4l2_close(struct f
>
> if (r) {
> printk(KERN_INFO "%s: Final disconnect\n", __func__);
> - usbvision_release(usbvision);
> return 0;
> }
>
> @@ -409,6 +408,11 @@ static int usbvision_v4l2_close(struct f
> return v4l2_fh_release(file);
> }
>
> +static void usbvision_video_device_release(struct video_device *vdev)
> +{
> + struct usb_usbvision *usbvision = video_get_drvdata(vdev);
> + usbvision_release(usbvision);
> +}
>
> /*
> * usbvision_ioctl()
> @@ -1181,7 +1185,7 @@ static struct video_device usbvision_vid
> .fops = &usbvision_fops,
> .ioctl_ops = &usbvision_ioctl_ops,
> .name = "usbvision-video",
> - .release = video_device_release_empty,
> + .release = usbvision_video_device_release,
> .tvnorms = USBVISION_NORMS,
> };
>
> --- a/drivers/media/v4l2-core/v4l2-dev.c
> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> @@ -206,7 +206,10 @@ static void v4l2_device_release(struct d
> }
> #endif
>
> - /* Do not call v4l2_device_put if there is no release callback set.
> + /*
> + * Decrease v4l2_device refcount
> + *
> + * Do not call v4l2_device_put if there is no release callback set.
> * Drivers that have no v4l2_device release callback might free the
> * v4l2_dev instance in the video_device release callback below, so we
> * must perform this check here.
> @@ -214,16 +217,12 @@ static void v4l2_device_release(struct d
> * TODO: In the long run all drivers that use v4l2_device should use the
> * v4l2_device release callback. This check will then be unnecessary.
> */
> - if (v4l2_dev->release == NULL)
> - v4l2_dev = NULL;
> + if (v4l2_dev->release)
> + v4l2_device_put(v4l2_dev);
>
> /* Release video_device and perform other
> cleanups as needed. */
> vdev->release(vdev);
> -
> - /* Decrease v4l2_device refcount */
> - if (v4l2_dev)
> - v4l2_device_put(v4l2_dev);
> }
>
> static struct class video_class = {
> --
#syz test: https://github.com/google/kasan.git ae179410
Hello,
syzbot has tested the proposed patch but the reproducer still triggered crash:
WARNING in kernfs_remove_by_name_ns
------------[ cut here ]------------
kernfs: can not remove 'version', no directory
WARNING: CPU: 1 PID: 94 at fs/kernfs/dir.c:1507 kernfs_remove_by_name_ns+0x98/0xb0 fs/kernfs/dir.c:1507
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 94 Comm: kworker/1:2 Not tainted 5.5.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xef/0x16e lib/dump_stack.c:118
panic+0x2aa/0x6e1 kernel/panic.c:221
__warn.cold+0x2f/0x30 kernel/panic.c:582
report_bug+0x27b/0x2f0 lib/bug.c:195
fixup_bug arch/x86/kernel/traps.c:174 [inline]
fixup_bug arch/x86/kernel/traps.c:169 [inline]
do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:267
do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:kernfs_remove_by_name_ns+0x98/0xb0 fs/kernfs/dir.c:1507
Code: b1 ff 48 c7 c7 20 13 1d 87 41 bc fe ff ff ff e8 2e fe fe 03 eb d9 e8 47 4d b1 ff 4c 89 e6 48 c7 c7 c0 51 f1 85 e8 20 33 86 ff <0f> 0b 41 bc fe ff ff ff eb bb 0f 1f 40 00 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffff8881d5d47708 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8881cba58390 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff812959ad RDI: ffffed103aba8ed3
RBP: 0000000000000000 R08: ffff8881d6d2c980 R09: fffffbfff1269aae
R10: fffffbfff1269aad R11: ffffffff8934d56f R12: ffffffff8671eb40
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000000c
sysfs_remove_file include/linux/sysfs.h:536 [inline]
device_remove_file+0x25/0x30 drivers/base/core.c:1869
usbvision_remove_sysfs drivers/media/usb/usbvision/usbvision-video.c:287 [inline]
usbvision_release+0x88/0x1c0 drivers/media/usb/usbvision/usbvision-video.c:1360
v4l2_device_release+0x29a/0x3e0 drivers/media/v4l2-core/v4l2-dev.c:225
device_release+0x71/0x200 drivers/base/core.c:1358
kobject_cleanup lib/kobject.c:693 [inline]
kobject_release lib/kobject.c:722 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x256/0x550 lib/kobject.c:739
put_device drivers/base/core.c:2586 [inline]
device_unregister+0x34/0xc0 drivers/base/core.c:2697
video_unregister_device+0xa2/0xc0 drivers/media/v4l2-core/v4l2-dev.c:1075
usbvision_unregister_video drivers/media/usb/usbvision/usbvision-video.c:1255 [inline]
usbvision_unregister_video+0xfb/0x120 drivers/media/usb/usbvision/usbvision-video.c:1242
usbvision_release+0x10d/0x1c0 drivers/media/usb/usbvision/usbvision-video.c:1361
usbvision_disconnect+0x171/0x1e0 drivers/media/usb/usbvision/usbvision-video.c:1593
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+0x2eb/0x5a0 drivers/base/bus.c:532
device_del+0x481/0xd30 drivers/base/core.c:2664
usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1237
usb_disconnect+0x293/0x900 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+0x1a1d/0x4300 drivers/usb/core/hub.c:5552
process_one_work+0x945/0x15c0 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
Kernel Offset: disabled
Rebooting in 86400 seconds..
Tested on:
commit: ae179410 usb: gadget: add raw-gadget interface
git tree: https://github.com/google/kasan.git
console output: https://syzkaller.appspot.com/x/log.txt?x=133b3611e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ad1d751a3a72ae57
dashboard link: https://syzkaller.appspot.com/bug?extid=75287f75e2fedd69d680
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
patch: https://syzkaller.appspot.com/x/patch.diff?x=15921b69e00000
This would work but another approach would be to to allocate "usbvision"
with devm_kzalloc(&dev->dev,... I believe that would postpone the free
enough to solve the use after free but I hadn't tested it yet. But
other drivers do that so hopefully it works.
regards,
dan carpenter