* 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
[parent not found: <20200123102707.2596-1-hdanton@sina.com>]
* 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
[parent not found: <20200124022847.11244-1-hdanton@sina.com>]
* 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
[parent not found: <20200214121447.13612-1-hdanton@sina.com>]
* 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
[parent not found: <20200214124825.12568-1-hdanton@sina.com>]
* 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)
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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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