* KASAN: use-after-free Read in v4l2_release (3)
@ 2020-01-08 20:24 syzbot
2020-01-22 22:58 ` syzbot
[not found] ` <20200123102707.2596-1-hdanton@sina.com>
0 siblings, 2 replies; 12+ messages in thread
From: syzbot @ 2020-01-08 20:24 UTC (permalink / raw)
To: andreyknvl, bnvandana, hverkuil-cisco, laurent.pinchart,
linux-kernel, linux-media, linux-usb, mchehab, syzkaller-bugs
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: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
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 syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: KASAN: use-after-free Read in v4l2_release (3)
2020-01-08 20:24 KASAN: use-after-free Read in v4l2_release (3) syzbot
@ 2020-01-22 22:58 ` syzbot
[not found] ` <20200123102707.2596-1-hdanton@sina.com>
1 sibling, 0 replies; 12+ messages in thread
From: syzbot @ 2020-01-22 22:58 UTC (permalink / raw)
To: andreyknvl, bnvandana, hverkuil-cisco, laurent.pinchart,
linux-kernel, linux-media, linux-usb, mchehab, syzkaller-bugs
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: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
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
==================================================================
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: KASAN: use-after-free Read in v4l2_release (3)
[not found] ` <20200123102707.2596-1-hdanton@sina.com>
@ 2020-01-23 12:19 ` Laurent Pinchart
[not found] ` <20200124022847.11244-1-hdanton@sina.com>
` (2 subsequent siblings)
3 siblings, 0 replies; 12+ messages in thread
From: Laurent Pinchart @ 2020-01-23 12:19 UTC (permalink / raw)
To: Hillf Danton
Cc: syzbot, andreyknvl, bnvandana, hverkuil-cisco, linux-kernel,
linux-media, linux-usb, mchehab, syzkaller-bugs
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: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
> >
> > 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
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: KASAN: use-after-free Read in v4l2_release (3)
[not found] ` <20200124022847.11244-1-hdanton@sina.com>
@ 2020-01-24 12:41 ` Andrey Konovalov
2020-01-24 12:54 ` syzbot
0 siblings, 1 reply; 12+ messages in thread
From: Andrey Konovalov @ 2020-01-24 12:41 UTC (permalink / raw)
To: Hillf Danton
Cc: Laurent Pinchart, syzbot, bnvandana, hverkuil-cisco, LKML,
linux-media, USB list, Mauro Carvalho Chehab, syzkaller-bugs,
Hans Verkuil
[-- Attachment #1: Type: text/plain, Size: 4824 bytes --]
On Fri, Jan 24, 2020 at 3:29 AM Hillf Danton <hdanton@sina.com> 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: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
> > > >
> > > > 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 <hdanton@sina.com>
>
> 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 <syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com>
> Fixes: 2aa689dd8057 ("[media] usbvision: embed video_device")
> Cc: Hans Verkuil <hans.verkuil@cisco.com>
> Signed-off-by: Hillf Danton <hdanton@sina.com>
> ---
>
> --- 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
[-- Attachment #2: usbvision.patch --]
[-- Type: application/x-patch, Size: 2585 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: KASAN: use-after-free Read in v4l2_release (3)
2020-01-24 12:41 ` Andrey Konovalov
@ 2020-01-24 12:54 ` syzbot
0 siblings, 0 replies; 12+ messages in thread
From: syzbot @ 2020-01-24 12:54 UTC (permalink / raw)
To: andreyknvl, bnvandana, hans.verkuil, hdanton, hverkuil-cisco,
laurent.pinchart, linux-kernel, linux-media, linux-usb, mchehab,
syzkaller-bugs
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
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: KASAN: use-after-free Read in v4l2_release (3)
[not found] ` <20200123102707.2596-1-hdanton@sina.com>
2020-01-23 12:19 ` Laurent Pinchart
[not found] ` <20200124022847.11244-1-hdanton@sina.com>
@ 2020-01-24 14:10 ` Dan Carpenter
2020-01-24 14:13 ` [PATCH] media: usbvision: Fix a use after free in v4l2_release() Dan Carpenter
3 siblings, 0 replies; 12+ messages in thread
From: Dan Carpenter @ 2020-01-24 14:10 UTC (permalink / raw)
To: Hillf Danton
Cc: syzbot, andreyknvl, bnvandana, hverkuil-cisco, laurent.pinchart,
linux-kernel, linux-media, linux-usb, mchehab, syzkaller-bugs
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
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH] media: usbvision: Fix a use after free in v4l2_release()
[not found] ` <20200123102707.2596-1-hdanton@sina.com>
` (2 preceding siblings ...)
2020-01-24 14:10 ` Dan Carpenter
@ 2020-01-24 14:13 ` Dan Carpenter
2020-02-14 10:06 ` Hans Verkuil
3 siblings, 1 reply; 12+ messages in thread
From: Dan Carpenter @ 2020-01-24 14:13 UTC (permalink / raw)
To: Hans Verkuil, syzbot, Hillf Danton
Cc: Alan Stern, Allison Randal, Greg Kroah-Hartman, Souptick Joarder,
andreyknvl, bnvandana, laurent.pinchart, linux-kernel,
linux-media, linux-usb, mchehab, syzkaller-bugs
Syzbot triggered a use after free in v5.5-rc6:
BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
Allocated by task 94:
usbvision_alloc drivers/media/usb/usbvision/usbvision-video.c:1315 [inline]
usbvision_probe.cold+0x5c5/0x1f21 drivers/media/usb/usbvision/usbvision-video.c:1469
Freed by task 1913:
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
The problem is that the v4l2_release() calls usbvision_release() which
frees "usbvision" but v4l2_release() still wants to use
"usbvision->vdev". One solution is to make this devm_ allocated memory
so the memory isn't freed until later.
Reported-by: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
I copied this idea from a different driver, but I haven't tested it.
I wanted to try the #syz fix command to see if it works.
drivers/media/usb/usbvision/usbvision-video.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
index 93d36aab824f..07b4763062c4 100644
--- a/drivers/media/usb/usbvision/usbvision-video.c
+++ b/drivers/media/usb/usbvision/usbvision-video.c
@@ -1312,7 +1312,7 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
{
struct usb_usbvision *usbvision;
- usbvision = kzalloc(sizeof(*usbvision), GFP_KERNEL);
+ usbvision = devm_kzalloc(&dev->dev, sizeof(*usbvision), GFP_KERNEL);
if (!usbvision)
return NULL;
@@ -1336,7 +1336,6 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
v4l2_ctrl_handler_free(&usbvision->hdl);
v4l2_device_unregister(&usbvision->v4l2_dev);
err_free:
- kfree(usbvision);
return NULL;
}
@@ -1361,7 +1360,6 @@ static void usbvision_release(struct usb_usbvision *usbvision)
v4l2_ctrl_handler_free(&usbvision->hdl);
v4l2_device_unregister(&usbvision->v4l2_dev);
- kfree(usbvision);
PDEBUG(DBG_PROBE, "success");
}
--
2.11.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH] media: usbvision: Fix a use after free in v4l2_release()
2020-01-24 14:13 ` [PATCH] media: usbvision: Fix a use after free in v4l2_release() Dan Carpenter
@ 2020-02-14 10:06 ` Hans Verkuil
2020-02-14 11:22 ` Laurent Pinchart
0 siblings, 1 reply; 12+ messages in thread
From: Hans Verkuil @ 2020-02-14 10:06 UTC (permalink / raw)
To: Dan Carpenter, syzbot, Hillf Danton
Cc: Alan Stern, Allison Randal, Greg Kroah-Hartman, Souptick Joarder,
andreyknvl, bnvandana, laurent.pinchart, linux-kernel,
linux-media, linux-usb, mchehab, syzkaller-bugs
On 1/24/20 3:13 PM, Dan Carpenter wrote:
> Syzbot triggered a use after free in v5.5-rc6:
>
> BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
>
> Allocated by task 94:
> usbvision_alloc drivers/media/usb/usbvision/usbvision-video.c:1315 [inline]
> usbvision_probe.cold+0x5c5/0x1f21 drivers/media/usb/usbvision/usbvision-video.c:1469
>
> Freed by task 1913:
> 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
>
> The problem is that the v4l2_release() calls usbvision_release() which
> frees "usbvision" but v4l2_release() still wants to use
> "usbvision->vdev". One solution is to make this devm_ allocated memory
> so the memory isn't freed until later.
devm_ allocated memory is freed after disconnect, so I doubt this will help, or at
best it will just move the problem elsewhere.
The right approach would be to use the release() callback from struct v4l2_device:
that's called when the very last open filehandle is closed.
But I'm not sure if it is worth the effort. The usbvision driver is a mess and
personally I think it should be deprecated.
Regards,
Hans
>
> Reported-by: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> I copied this idea from a different driver, but I haven't tested it.
> I wanted to try the #syz fix command to see if it works.
>
> drivers/media/usb/usbvision/usbvision-video.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
> index 93d36aab824f..07b4763062c4 100644
> --- a/drivers/media/usb/usbvision/usbvision-video.c
> +++ b/drivers/media/usb/usbvision/usbvision-video.c
> @@ -1312,7 +1312,7 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
> {
> struct usb_usbvision *usbvision;
>
> - usbvision = kzalloc(sizeof(*usbvision), GFP_KERNEL);
> + usbvision = devm_kzalloc(&dev->dev, sizeof(*usbvision), GFP_KERNEL);
> if (!usbvision)
> return NULL;
>
> @@ -1336,7 +1336,6 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
> v4l2_ctrl_handler_free(&usbvision->hdl);
> v4l2_device_unregister(&usbvision->v4l2_dev);
> err_free:
> - kfree(usbvision);
> return NULL;
> }
>
> @@ -1361,7 +1360,6 @@ static void usbvision_release(struct usb_usbvision *usbvision)
>
> v4l2_ctrl_handler_free(&usbvision->hdl);
> v4l2_device_unregister(&usbvision->v4l2_dev);
> - kfree(usbvision);
>
> PDEBUG(DBG_PROBE, "success");
> }
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] media: usbvision: Fix a use after free in v4l2_release()
2020-02-14 10:06 ` Hans Verkuil
@ 2020-02-14 11:22 ` Laurent Pinchart
2020-02-14 11:30 ` Hans Verkuil
[not found] ` <20200214121447.13612-1-hdanton@sina.com>
0 siblings, 2 replies; 12+ messages in thread
From: Laurent Pinchart @ 2020-02-14 11:22 UTC (permalink / raw)
To: Hans Verkuil
Cc: Dan Carpenter, syzbot, Hillf Danton, Alan Stern, Allison Randal,
Greg Kroah-Hartman, Souptick Joarder, andreyknvl, bnvandana,
linux-kernel, linux-media, linux-usb, mchehab, syzkaller-bugs
Hi Hans,
On Fri, Feb 14, 2020 at 11:06:36AM +0100, Hans Verkuil wrote:
> On 1/24/20 3:13 PM, Dan Carpenter wrote:
> > Syzbot triggered a use after free in v5.5-rc6:
> >
> > BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
> >
> > Allocated by task 94:
> > usbvision_alloc drivers/media/usb/usbvision/usbvision-video.c:1315 [inline]
> > usbvision_probe.cold+0x5c5/0x1f21 drivers/media/usb/usbvision/usbvision-video.c:1469
> >
> > Freed by task 1913:
> > 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
> >
> > The problem is that the v4l2_release() calls usbvision_release() which
> > frees "usbvision" but v4l2_release() still wants to use
> > "usbvision->vdev". One solution is to make this devm_ allocated memory
> > so the memory isn't freed until later.
>
> devm_ allocated memory is freed after disconnect, so I doubt this will help, or at
> best it will just move the problem elsewhere.
Yes, devm_*alloc is evil :-( It has spread to many drivers and is used
incorrectly in most cases.
> The right approach would be to use the release() callback from struct v4l2_device:
> that's called when the very last open filehandle is closed.
Hillf Danton has sent a patch to do so in the "Re: KASAN: use-after-free
Read in v4l2_release (3)" thread. Have you seen it ?
> But I'm not sure if it is worth the effort. The usbvision driver is a mess and
> personally I think it should be deprecated.
I agree.
> > Reported-by: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > I copied this idea from a different driver, but I haven't tested it.
> > I wanted to try the #syz fix command to see if it works.
> >
> > drivers/media/usb/usbvision/usbvision-video.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
> > index 93d36aab824f..07b4763062c4 100644
> > --- a/drivers/media/usb/usbvision/usbvision-video.c
> > +++ b/drivers/media/usb/usbvision/usbvision-video.c
> > @@ -1312,7 +1312,7 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
> > {
> > struct usb_usbvision *usbvision;
> >
> > - usbvision = kzalloc(sizeof(*usbvision), GFP_KERNEL);
> > + usbvision = devm_kzalloc(&dev->dev, sizeof(*usbvision), GFP_KERNEL);
> > if (!usbvision)
> > return NULL;
> >
> > @@ -1336,7 +1336,6 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
> > v4l2_ctrl_handler_free(&usbvision->hdl);
> > v4l2_device_unregister(&usbvision->v4l2_dev);
> > err_free:
> > - kfree(usbvision);
> > return NULL;
> > }
> >
> > @@ -1361,7 +1360,6 @@ static void usbvision_release(struct usb_usbvision *usbvision)
> >
> > v4l2_ctrl_handler_free(&usbvision->hdl);
> > v4l2_device_unregister(&usbvision->v4l2_dev);
> > - kfree(usbvision);
> >
> > PDEBUG(DBG_PROBE, "success");
> > }
--
Regards,
Laurent Pinchart
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] media: usbvision: Fix a use after free in v4l2_release()
2020-02-14 11:22 ` Laurent Pinchart
@ 2020-02-14 11:30 ` Hans Verkuil
[not found] ` <20200214121447.13612-1-hdanton@sina.com>
1 sibling, 0 replies; 12+ messages in thread
From: Hans Verkuil @ 2020-02-14 11:30 UTC (permalink / raw)
To: Laurent Pinchart
Cc: Dan Carpenter, syzbot, Hillf Danton, Alan Stern, Allison Randal,
Greg Kroah-Hartman, Souptick Joarder, andreyknvl, bnvandana,
linux-kernel, linux-media, linux-usb, mchehab, syzkaller-bugs
On 2/14/20 12:22 PM, Laurent Pinchart wrote:
> Hi Hans,
>
> On Fri, Feb 14, 2020 at 11:06:36AM +0100, Hans Verkuil wrote:
>> On 1/24/20 3:13 PM, Dan Carpenter wrote:
>>> Syzbot triggered a use after free in v5.5-rc6:
>>>
>>> BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459
>>>
>>> Allocated by task 94:
>>> usbvision_alloc drivers/media/usb/usbvision/usbvision-video.c:1315 [inline]
>>> usbvision_probe.cold+0x5c5/0x1f21 drivers/media/usb/usbvision/usbvision-video.c:1469
>>>
>>> Freed by task 1913:
>>> 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
>>>
>>> The problem is that the v4l2_release() calls usbvision_release() which
>>> frees "usbvision" but v4l2_release() still wants to use
>>> "usbvision->vdev". One solution is to make this devm_ allocated memory
>>> so the memory isn't freed until later.
>>
>> devm_ allocated memory is freed after disconnect, so I doubt this will help, or at
>> best it will just move the problem elsewhere.
>
> Yes, devm_*alloc is evil :-( It has spread to many drivers and is used
> incorrectly in most cases.
>
>> The right approach would be to use the release() callback from struct v4l2_device:
>> that's called when the very last open filehandle is closed.
>
> Hillf Danton has sent a patch to do so in the "Re: KASAN: use-after-free
> Read in v4l2_release (3)" thread. Have you seen it ?
Ah, that was never mailed to linux-media, so never ended up in patchwork. And
if it ain't in patchwork, then I don't know about it :-)
Hillf, if you want your patch to be merged, then make sure it is CC-ed to
linux-media as well.
Regards,
Hans
>
>> But I'm not sure if it is worth the effort. The usbvision driver is a mess and
>> personally I think it should be deprecated.
>
> I agree.
>
>>> Reported-by: syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com
>>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>>> ---
>>> I copied this idea from a different driver, but I haven't tested it.
>>> I wanted to try the #syz fix command to see if it works.
>>>
>>> drivers/media/usb/usbvision/usbvision-video.c | 4 +---
>>> 1 file changed, 1 insertion(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
>>> index 93d36aab824f..07b4763062c4 100644
>>> --- a/drivers/media/usb/usbvision/usbvision-video.c
>>> +++ b/drivers/media/usb/usbvision/usbvision-video.c
>>> @@ -1312,7 +1312,7 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
>>> {
>>> struct usb_usbvision *usbvision;
>>>
>>> - usbvision = kzalloc(sizeof(*usbvision), GFP_KERNEL);
>>> + usbvision = devm_kzalloc(&dev->dev, sizeof(*usbvision), GFP_KERNEL);
>>> if (!usbvision)
>>> return NULL;
>>>
>>> @@ -1336,7 +1336,6 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
>>> v4l2_ctrl_handler_free(&usbvision->hdl);
>>> v4l2_device_unregister(&usbvision->v4l2_dev);
>>> err_free:
>>> - kfree(usbvision);
>>> return NULL;
>>> }
>>>
>>> @@ -1361,7 +1360,6 @@ static void usbvision_release(struct usb_usbvision *usbvision)
>>>
>>> v4l2_ctrl_handler_free(&usbvision->hdl);
>>> v4l2_device_unregister(&usbvision->v4l2_dev);
>>> - kfree(usbvision);
>>>
>>> PDEBUG(DBG_PROBE, "success");
>>> }
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] media: usbvision: Fix a use after free in v4l2_release()
[not found] ` <20200214121447.13612-1-hdanton@sina.com>
@ 2020-02-14 12:21 ` Hans Verkuil
[not found] ` <20200214124825.12568-1-hdanton@sina.com>
1 sibling, 0 replies; 12+ messages in thread
From: Hans Verkuil @ 2020-02-14 12:21 UTC (permalink / raw)
To: Hillf Danton
Cc: Laurent Pinchart, Dan Carpenter, syzbot, Alan Stern,
Allison Randal, Greg Kroah-Hartman, Souptick Joarder, andreyknvl,
bnvandana, linux-kernel, linux-media, linux-usb, mchehab,
syzkaller-bugs
On 2/14/20 1:14 PM, Hillf Danton wrote:
>
> On Fri, 14 Feb 2020 12:30:29 +0100 Hans Verkuil wrote:
>>
>> Hillf, if you want your patch to be merged, then make sure it is CC-ed to
>> linux-media as well.
>
> Please pick it up if it makes a sense to you and it was sent with
> linux-media added on the Cc list as it is known for a while that
> my mail agent is rejected @vger.kernel.org for what I am not clear
> about. It makes my day occasionally :P
I don't I ever received the full patch, only replies to your patch.
Please mail your patch directly to me so I have a clean version.
Regards,
Hans
>
> Thanks
> Hillf
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] media: usbvision: Fix a use after free in v4l2_release()
[not found] ` <20200214124825.12568-1-hdanton@sina.com>
@ 2020-02-14 13:34 ` Hans Verkuil
0 siblings, 0 replies; 12+ messages in thread
From: Hans Verkuil @ 2020-02-14 13:34 UTC (permalink / raw)
To: Hillf Danton
Cc: Laurent Pinchart, Dan Carpenter, syzbot, Alan Stern,
Allison Randal, Greg Kroah-Hartman, Souptick Joarder, andreyknvl,
bnvandana, linux-kernel, linux-media, linux-usb, mchehab,
syzkaller-bugs
On 2/14/20 1:48 PM, Hillf Danton wrote:
>
> On Fri, 14 Feb 2020 13:21:03 +0100 Hans Verkuil wrote:
>> On 2/14/20 1:14 PM, Hillf Danton wrote:
>>>
>>> On Fri, 14 Feb 2020 12:30:29 +0100 Hans Verkuil wrote:
>>>>
>>>> Hillf, if you want your patch to be merged, then make sure it is CC-ed to
>>>> linux-media as well.
>>>
>>> Please pick it up if it makes a sense to you and it was sent with
>>> linux-media added on the Cc list as it is known for a while that
>>> my mail agent is rejected @vger.kernel.org for what I am not clear
>>> about. It makes my day occasionally :P
>>
>> I don't I ever received the full patch, only replies to your patch.
>>
>
> =========
> Please take a look at the Cc tag in the snippet from
> https://lore.kernel.org/lkml/b1d071e2-0428-a08c-392d-3ca5d4a7e710@xs4all.nl/T/#m13f2c16b7cd1892f6a0b58b72ce37979cb6940b9
>
>
>> Subject: [PATCH] media: usbvision: add the release callback for video device
>> From: Hillf Danton <hdanton@sina.com>
>>
>> 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 <syzbot+75287f75e2fedd69d680@syzkaller.appspotmail.com>
>> Fixes: 2aa689dd8057 ("[media] usbvision: embed video_device")
>> Cc: Hans Verkuil <hans.verkuil@cisco.com>
Ah, my work email. And I always delete posts mailed to that if it is also CC-ed
to linux-media. Which didn't actually arrive there in your case. And it's no longer
in my trash folder either.
So please mail me a properly formatted patch so I can forward it to linux-media
for you.
Regards,
Hans
>> Signed-off-by: Hillf Danton <hdanton@sina.com>
>> ---
> =========
>
>> Please mail your patch directly to me so I have a clean version.
>
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2020-02-14 13:34 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-08 20:24 KASAN: use-after-free Read in v4l2_release (3) syzbot
2020-01-22 22:58 ` syzbot
[not found] ` <20200123102707.2596-1-hdanton@sina.com>
2020-01-23 12:19 ` Laurent Pinchart
[not found] ` <20200124022847.11244-1-hdanton@sina.com>
2020-01-24 12:41 ` Andrey Konovalov
2020-01-24 12:54 ` syzbot
2020-01-24 14:10 ` Dan Carpenter
2020-01-24 14:13 ` [PATCH] media: usbvision: Fix a use after free in v4l2_release() Dan Carpenter
2020-02-14 10:06 ` Hans Verkuil
2020-02-14 11:22 ` Laurent Pinchart
2020-02-14 11:30 ` Hans Verkuil
[not found] ` <20200214121447.13612-1-hdanton@sina.com>
2020-02-14 12:21 ` Hans Verkuil
[not found] ` <20200214124825.12568-1-hdanton@sina.com>
2020-02-14 13:34 ` Hans Verkuil
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