* Re: KASAN: use-after-free Read in v4l2_fh_open
2021-02-15 15:18 KASAN: use-after-free Read in v4l2_fh_open syzbot
@ 2021-05-04 21:28 ` SyzScope
2024-03-02 10:56 ` Hillf Danton
` (2 subsequent siblings)
3 siblings, 0 replies; 8+ messages in thread
From: SyzScope @ 2021-05-04 21:28 UTC (permalink / raw)
To: linux-kernel, linux-media, mchehab
Hi,
This is SyzScope, a research project that aims to reveal high-risk
primitives from a seemingly low-risk bug (UAF/OOB read, WARNING, BUG, etc.).
We are currently testing seemingly low-risk bugs on syzbot's open
section(https://syzkaller.appspot.com/upstream), and try to reach out to
kernel developers as long as SyzScope discovers any high-risk primitives.
Please let us know if SyzScope indeed helps, and any suggestions/feedback.
Regrading the bug "KASAN: use-after-free Read in v4l2_fh_open", SyzScope
reports 1 memory write capability.
The detailed comments can be found at
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-v4l2_fh_open
On 2/15/2021 7:18 AM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 291009f6 Merge tag 'pm-5.11-rc8' of git://git.kernel.org/p..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17260814d00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6a218c95bd23063a
> dashboard link: https://syzkaller.appspot.com/bug?extid=b2391895514ed9ef4a8e
> compiler: Debian clang version 11.0.1-2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14ec5814d00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17179dd4d00000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+b2391895514ed9ef4a8e@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: use-after-free in v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
> BUG: KASAN: use-after-free in v4l2_fh_open+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63
> Read of size 8 at addr ffff8880228b88b8 by task v4l_id/18349
>
> CPU: 1 PID: 18349 Comm: v4l_id Not tainted 5.11.0-rc7-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:79 [inline]
> dump_stack+0x137/0x1be lib/dump_stack.c:120
> print_address_description+0x5f/0x3a0 mm/kasan/report.c:230
> __kasan_report mm/kasan/report.c:396 [inline]
> kasan_report+0x15e/0x200 mm/kasan/report.c:413
> v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
> v4l2_fh_open+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63
> em28xx_v4l2_open+0x15c/0xa60 drivers/media/usb/em28xx/em28xx-video.c:2163
> v4l2_open+0x229/0x360 drivers/media/v4l2-core/v4l2-dev.c:423
> chrdev_open+0x4a0/0x570 fs/char_dev.c:414
> do_dentry_open+0x7cb/0x1010 fs/open.c:817
> do_open fs/namei.c:3254 [inline]
> path_openat+0x2791/0x37a0 fs/namei.c:3371
> do_filp_open+0x191/0x3a0 fs/namei.c:3398
> do_sys_openat2+0xba/0x380 fs/open.c:1172
> do_sys_open fs/open.c:1188 [inline]
> __do_sys_open fs/open.c:1196 [inline]
> __se_sys_open fs/open.c:1192 [inline]
> __x64_sys_open+0x1af/0x1e0 fs/open.c:1192
> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
> RIP: 0033:0x7fdd62b00840
> Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24
> RSP: 002b:00007ffe8bb255b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
> RAX: ffffffffffffffda RBX: 00007ffe8bb25728 RCX: 00007fdd62b00840
> RDX: 00007fdd62aecea0 RSI: 0000000000000000 RDI: 00007ffe8bb26f1c
> RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000002 R11: 0000000000000246 R12: 000055f8a7dee8d0
> R13: 00007ffe8bb25720 R14: 0000000000000000 R15: 0000000000000000
>
> The buggy address belongs to the page:
> page:00000000b7dd9778 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x228b8
> flags: 0xfff00000000000()
> raw: 00fff00000000000 ffffea0000580108 ffff88813fffb910 0000000000000000
> raw: 0000000000000000 0000000000000002 00000000ffffff7f 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff8880228b8780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> ffff8880228b8800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>> ffff8880228b8880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> ^
> ffff8880228b8900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> ffff8880228b8980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> ==================================================================
>
>
> ---
> This report 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 issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> syzbot can test patches for this issue, for details see:
> https://goo.gl/tpsmEJ#testing-patches
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: KASAN: use-after-free Read in v4l2_fh_open
2021-02-15 15:18 KASAN: use-after-free Read in v4l2_fh_open syzbot
2021-05-04 21:28 ` SyzScope
@ 2024-03-02 10:56 ` Hillf Danton
2024-03-02 13:02 ` [syzbot] [usb?] [media?] " syzbot
2024-03-02 23:07 ` Hillf Danton
2024-03-03 1:43 ` Hillf Danton
3 siblings, 1 reply; 8+ messages in thread
From: Hillf Danton @ 2024-03-02 10:56 UTC (permalink / raw)
To: syzbot; +Cc: linux-kernel, syzkaller-bugs
On Mon, 15 Feb 2021 07:18:22 -0800
> syzbot found the following issue on:
>
> HEAD commit: 291009f6 Merge tag 'pm-5.11-rc8' of git://git.kernel.org/p..
> git tree: upstream
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17179dd4d00000
#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
--- x/drivers/media/usb/em28xx/em28xx-video.c
+++ y/drivers/media/usb/em28xx/em28xx-video.c
@@ -2152,6 +2152,10 @@ static int em28xx_v4l2_open(struct file
if (mutex_lock_interruptible(&dev->lock))
return -ERESTARTSYS;
+ if (!dev->v4l2) {
+ mutex_unlock(&dev->lock);
+ return -ENODEV;
+ }
ret = v4l2_fh_open(filp);
if (ret) {
dev_err(&dev->intf->dev,
@@ -2161,6 +2165,7 @@ static int em28xx_v4l2_open(struct file
return ret;
}
+ v4l2 = dev->v4l2;
if (v4l2->users == 0) {
em28xx_set_mode(dev, EM28XX_ANALOG_MODE);
--
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [syzbot] [usb?] [media?] KASAN: use-after-free Read in v4l2_fh_open
2024-03-02 10:56 ` Hillf Danton
@ 2024-03-02 13:02 ` syzbot
0 siblings, 0 replies; 8+ messages in thread
From: syzbot @ 2024-03-02 13:02 UTC (permalink / raw)
To: hdanton, linux-kernel, syzkaller-bugs
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in v4l2_open
==================================================================
BUG: KASAN: slab-use-after-free in v4l2_open+0x342/0x360 drivers/media/v4l2-core/v4l2-dev.c:432
Read of size 4 at addr ffff888024454800 by task v4l_id/5646
CPU: 1 PID: 5646 Comm: v4l_id Not tainted 6.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b5/0x2a0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x163/0x510 mm/kasan/report.c:488
kasan_report+0xcd/0x100 mm/kasan/report.c:601
v4l2_open+0x342/0x360 drivers/media/v4l2-core/v4l2-dev.c:432
chrdev_open+0x50f/0x5d0 fs/char_dev.c:414
do_dentry_open+0x8fd/0x1590 fs/open.c:953
path_openat+0x280d/0x31d0 fs/namei.c:3645
do_filp_open+0x26d/0x500 fs/namei.c:3829
do_sys_openat2+0x12f/0x1c0 fs/open.c:1404
do_sys_open fs/open.c:1419 [inline]
__do_sys_openat fs/open.c:1435 [inline]
__se_sys_openat fs/open.c:1430 [inline]
__x64_sys_openat+0x247/0x290 fs/open.c:1430
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f3dabb169a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffc466ecd40 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffc466ecf58 RCX: 00007f3dabb169a4
RDX: 0000000000000000 RSI: 00007ffc466edf1e RDI: 00000000ffffff9c
RBP: 00007ffc466edf1e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc466ecf70 R14: 0000555aa0ec0670 R15: 00007f3dac0aca80
</TASK>
Allocated by task 8:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x60 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
kmalloc_trace+0x1e6/0x400 mm/slub.c:4012
kmalloc include/linux/slab.h:590 [inline]
kzalloc include/linux/slab.h:711 [inline]
em28xx_v4l2_init+0x107/0x2dc0 drivers/media/usb/em28xx/em28xx-video.c:2539
em28xx_init_extension+0x11f/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116
process_scheduled_works+0x96f/0x1490 kernel/workqueue.c:2633
worker_thread+0xa5f/0xff0 kernel/workqueue.c:2787
kthread+0x2cd/0x360 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243
Freed by task 8:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x60 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:589
poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kfree+0x14a/0x370 mm/slub.c:4409
em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline]
kref_put include/linux/kref.h:65 [inline]
em28xx_v4l2_init+0x1608/0x2dc0 drivers/media/usb/em28xx/em28xx-video.c:2908
em28xx_init_extension+0x11f/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116
process_scheduled_works+0x96f/0x1490 kernel/workqueue.c:2633
worker_thread+0xa5f/0xff0 kernel/workqueue.c:2787
kthread+0x2cd/0x360 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243
The buggy address belongs to the object at ffff888024454000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2048 bytes inside of
freed 8192-byte region [ffff888024454000, ffff888024456000)
The buggy address belongs to the physical page:
page:ffffea0000911400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24450
head:ffffea0000911400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888011442280 ffffea0001ede600 0000000000000005
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4658, tgid 4658 (S41dhcpcd), ts 32416679882, free_ts 32403418572
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0x3355/0x34e0 mm/page_alloc.c:3311
__alloc_pages+0x255/0x670 mm/page_alloc.c:4567
alloc_slab_page+0x5f/0x150 include/linux/gfp.h:238
new_slab+0x84/0x2f0 mm/slub.c:2354
___slab_alloc+0xc77/0x1310 mm/slub.c:3540
kmalloc_trace+0x276/0x400 mm/slub.c:3625
kmalloc include/linux/slab.h:590 [inline]
kzalloc include/linux/slab.h:711 [inline]
tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
tomoyo_init_log+0x1228/0x2130 security/tomoyo/audit.c:264
tomoyo_supervisor+0x37a/0x1370 security/tomoyo/common.c:2089
tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
tomoyo_env_perm+0x157/0x1f0 security/tomoyo/environ.c:63
tomoyo_find_next_domain+0x139a/0x1d40 security/tomoyo/domain.c:672
tomoyo_bprm_check_security+0x114/0x170 security/tomoyo/tomoyo.c:102
security_bprm_check+0x63/0xa0 security/security.c:1188
bprm_execve+0xa45/0x1840 fs/exec.c:1771
do_execveat_common+0x552/0x6f0 fs/exec.c:1984
do_execve fs/exec.c:2058 [inline]
__do_sys_execve fs/exec.c:2134 [inline]
__se_sys_execve fs/exec.c:2129 [inline]
__x64_sys_execve+0x92/0xa0 fs/exec.c:2129
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83
page last free pid 4657 tgid 4657 stack trace:
free_unref_page_prepare+0x94d/0xa60 include/linux/page_owner.h:24
free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486
__put_partials+0xeb/0x130 mm/slub.c:2453
put_cpu_partial+0x169/0x240 mm/slub.c:2997
__slab_free+0x2c3/0x400 mm/slub.c:4166
qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:163
kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3813 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
__do_kmalloc_node mm/slub.c:3980 [inline]
__kmalloc+0x1dd/0x540 mm/slub.c:3994
kmalloc include/linux/slab.h:594 [inline]
tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
tomoyo_path_perm+0x24d/0x5b0 security/tomoyo/file.c:151
security_inode_getattr+0xd3/0x120 security/security.c:2238
vfs_fstatat+0xca/0x1b0 fs/stat.c:173
__se_sys_newfstatat fs/stat.c:468 [inline]
__x64_sys_newfstatat+0xff/0x170 fs/stat.c:462
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Memory state around the buggy address:
ffff888024454700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888024454780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888024454800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888024454880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888024454900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Tested on:
commit: 5ad3cb0e Merge tag 'for-v6.8-rc2' of git://git.kernel...
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=163afbac180000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa01a41dc74de670
dashboard link: https://syzkaller.appspot.com/bug?extid=b2391895514ed9ef4a8e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=15d84096180000
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: KASAN: use-after-free Read in v4l2_fh_open
2021-02-15 15:18 KASAN: use-after-free Read in v4l2_fh_open syzbot
2021-05-04 21:28 ` SyzScope
2024-03-02 10:56 ` Hillf Danton
@ 2024-03-02 23:07 ` Hillf Danton
2024-03-02 23:39 ` [syzbot] [usb?] [media?] " syzbot
2024-03-03 1:43 ` Hillf Danton
3 siblings, 1 reply; 8+ messages in thread
From: Hillf Danton @ 2024-03-02 23:07 UTC (permalink / raw)
To: syzbot; +Cc: linux-kernel, syzkaller-bugs
On Mon, 15 Feb 2021 07:18:22 -0800
> syzbot found the following issue on:
>
> HEAD commit: 291009f6 Merge tag 'pm-5.11-rc8' of git://git.kernel.org/p..
> git tree: upstream
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17179dd4d00000
#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
--- x/drivers/media/usb/em28xx/em28xx-video.c
+++ y/drivers/media/usb/em28xx/em28xx-video.c
@@ -2152,6 +2152,10 @@ static int em28xx_v4l2_open(struct file
if (mutex_lock_interruptible(&dev->lock))
return -ERESTARTSYS;
+ if (!dev->v4l2) {
+ mutex_unlock(&dev->lock);
+ return -ENODEV;
+ }
ret = v4l2_fh_open(filp);
if (ret) {
dev_err(&dev->intf->dev,
@@ -2161,6 +2165,7 @@ static int em28xx_v4l2_open(struct file
return ret;
}
+ v4l2 = dev->v4l2;
if (v4l2->users == 0) {
em28xx_set_mode(dev, EM28XX_ANALOG_MODE);
@@ -2899,6 +2904,7 @@ unregister_dev:
v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
v4l2_device_unregister(&v4l2->v4l2_dev);
err:
+ video_unregister_device(&v4l2->vdev);
dev->v4l2 = NULL;
kref_put(&v4l2->ref, em28xx_free_v4l2);
mutex_unlock(&dev->lock);
--
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [syzbot] [usb?] [media?] KASAN: use-after-free Read in v4l2_fh_open
2024-03-02 23:07 ` Hillf Danton
@ 2024-03-02 23:39 ` syzbot
0 siblings, 0 replies; 8+ messages in thread
From: syzbot @ 2024-03-02 23:39 UTC (permalink / raw)
To: hdanton, linux-kernel, syzkaller-bugs
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in v4l2_open
==================================================================
BUG: KASAN: slab-use-after-free in v4l2_open+0x342/0x360 drivers/media/v4l2-core/v4l2-dev.c:432
Read of size 4 at addr ffff8880257b8800 by task v4l_id/5638
CPU: 1 PID: 5638 Comm: v4l_id Not tainted 6.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b5/0x2a0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x163/0x510 mm/kasan/report.c:488
kasan_report+0xcd/0x100 mm/kasan/report.c:601
v4l2_open+0x342/0x360 drivers/media/v4l2-core/v4l2-dev.c:432
chrdev_open+0x50f/0x5d0 fs/char_dev.c:414
do_dentry_open+0x8fd/0x1590 fs/open.c:953
path_openat+0x280d/0x31d0 fs/namei.c:3645
do_filp_open+0x26d/0x500 fs/namei.c:3829
do_sys_openat2+0x12f/0x1c0 fs/open.c:1404
do_sys_open fs/open.c:1419 [inline]
__do_sys_openat fs/open.c:1435 [inline]
__se_sys_openat fs/open.c:1430 [inline]
__x64_sys_openat+0x247/0x290 fs/open.c:1430
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fd0c998f9a4
Code: 24 20 48 8d 44 24 30 48 89 44 24 28 64 8b 04 25 18 00 00 00 85 c0 75 2c 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 60 48 8b 15 55 a4 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffe99c37580 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffe99c37798 RCX: 00007fd0c998f9a4
RDX: 0000000000000000 RSI: 00007ffe99c38f1e RDI: 00000000ffffff9c
RBP: 00007ffe99c38f1e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe99c377b0 R14: 000056109fa30670 R15: 00007fd0c9b4aa80
</TASK>
Allocated by task 5003:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x60 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
kmalloc_trace+0x1e6/0x400 mm/slub.c:4012
kmalloc include/linux/slab.h:590 [inline]
kzalloc include/linux/slab.h:711 [inline]
em28xx_v4l2_init+0x107/0x2dd0 drivers/media/usb/em28xx/em28xx-video.c:2539
em28xx_init_extension+0x11f/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116
process_scheduled_works+0x96f/0x1490 kernel/workqueue.c:2633
worker_thread+0xa5f/0xff0 kernel/workqueue.c:2787
kthread+0x2cd/0x360 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243
Freed by task 5003:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x60 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:589
poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kfree+0x14a/0x370 mm/slub.c:4409
em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline]
kref_put include/linux/kref.h:65 [inline]
em28xx_v4l2_init+0x1618/0x2dd0 drivers/media/usb/em28xx/em28xx-video.c:2909
em28xx_init_extension+0x11f/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1116
process_scheduled_works+0x96f/0x1490 kernel/workqueue.c:2633
worker_thread+0xa5f/0xff0 kernel/workqueue.c:2787
kthread+0x2cd/0x360 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243
The buggy address belongs to the object at ffff8880257b8000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2048 bytes inside of
freed 8192-byte region [ffff8880257b8000, ffff8880257ba000)
The buggy address belongs to the physical page:
page:ffffea000095ee00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x257b8
head:ffffea000095ee00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888011442280 ffffea00007c9c00 0000000000000006
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4662, tgid 4662 (dhcpcd), ts 31219348806, free_ts 31206911230
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0x3355/0x34e0 mm/page_alloc.c:3311
__alloc_pages+0x255/0x670 mm/page_alloc.c:4567
alloc_slab_page+0x5f/0x150 include/linux/gfp.h:238
new_slab+0x84/0x2f0 mm/slub.c:2354
___slab_alloc+0xc77/0x1310 mm/slub.c:3540
__kmalloc_node_track_caller+0x2e9/0x570 mm/slub.c:3625
kmalloc_reserve+0xf3/0x260 net/core/skbuff.c:582
__alloc_skb+0x19f/0x3d0 net/core/skbuff.c:651
alloc_skb include/linux/skbuff.h:1296 [inline]
netlink_dump+0x204/0xc70 net/netlink/af_netlink.c:2231
netlink_recvmsg+0x671/0x10f0 net/netlink/af_netlink.c:1990
____sys_recvmsg+0x28b/0x570 net/socket.c:1046
__sys_recvmsg+0x280/0x360 net/socket.c:2845
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
page last free pid 4662 tgid 4662 stack trace:
free_unref_page_prepare+0x94d/0xa60 include/linux/page_owner.h:24
free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486
__put_partials+0xeb/0x130 mm/slub.c:2453
put_cpu_partial+0x169/0x240 mm/slub.c:2997
__slab_free+0x2c3/0x400 mm/slub.c:4166
qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:163
kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3813 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
__do_kmalloc_node mm/slub.c:3980 [inline]
__kmalloc+0x1dd/0x540 mm/slub.c:3994
kmalloc include/linux/slab.h:594 [inline]
tomoyo_add_entry security/tomoyo/common.c:2023 [inline]
tomoyo_supervisor+0xdf1/0x1370 security/tomoyo/common.c:2095
tomoyo_path_permission+0x243/0x360 security/tomoyo/file.c:168
tomoyo_path_perm+0x442/0x5b0 security/tomoyo/file.c:838
security_inode_getattr+0xd3/0x120 security/security.c:2238
vfs_fstatat+0xca/0x1b0 fs/stat.c:173
__se_sys_newfstatat fs/stat.c:468 [inline]
__x64_sys_newfstatat+0xff/0x170 fs/stat.c:462
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x85/0x160 arch/x86/entry/common.c:83
Memory state around the buggy address:
ffff8880257b8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880257b8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880257b8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880257b8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880257b8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Tested on:
commit: 04b8076d Merge tag 'firewire-fixes-6.8-rc7' of git://g..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=10309dca180000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa01a41dc74de670
dashboard link: https://syzkaller.appspot.com/bug?extid=b2391895514ed9ef4a8e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=112b2732180000
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: KASAN: use-after-free Read in v4l2_fh_open
2021-02-15 15:18 KASAN: use-after-free Read in v4l2_fh_open syzbot
` (2 preceding siblings ...)
2024-03-02 23:07 ` Hillf Danton
@ 2024-03-03 1:43 ` Hillf Danton
2024-03-03 2:55 ` [syzbot] [usb?] [media?] " syzbot
3 siblings, 1 reply; 8+ messages in thread
From: Hillf Danton @ 2024-03-03 1:43 UTC (permalink / raw)
To: syzbot; +Cc: linux-kernel, syzkaller-bugs
On Mon, 15 Feb 2021 07:18:22 -0800
> syzbot found the following issue on:
>
> HEAD commit: 291009f6 Merge tag 'pm-5.11-rc8' of git://git.kernel.org/p..
> git tree: upstream
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17179dd4d00000
#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
--- x/drivers/media/usb/em28xx/em28xx-video.c
+++ y/drivers/media/usb/em28xx/em28xx-video.c
@@ -2152,6 +2152,10 @@ static int em28xx_v4l2_open(struct file
if (mutex_lock_interruptible(&dev->lock))
return -ERESTARTSYS;
+ if (!dev->v4l2) {
+ mutex_unlock(&dev->lock);
+ return -ENODEV;
+ }
ret = v4l2_fh_open(filp);
if (ret) {
dev_err(&dev->intf->dev,
@@ -2161,6 +2165,7 @@ static int em28xx_v4l2_open(struct file
return ret;
}
+ v4l2 = dev->v4l2;
if (v4l2->users == 0) {
em28xx_set_mode(dev, EM28XX_ANALOG_MODE);
@@ -2376,10 +2381,17 @@ static const struct v4l2_ioctl_ops video
#endif
};
+static void em28xx_video_device_release(struct video_device *vd)
+{
+ struct em28xx_v4l2 *v4l2 = container_of(vd, struct em28xx_v4l2, vdev);
+
+ kref_put(&v4l2->ref, em28xx_free_v4l2);
+}
+
static const struct video_device em28xx_video_template = {
.fops = &em28xx_v4l_fops,
.ioctl_ops = &video_ioctl_ops,
- .release = video_device_release_empty,
+ .release = em28xx_video_device_release,
.tvnorms = V4L2_STD_ALL,
};
@@ -2788,6 +2800,7 @@ static int em28xx_v4l2_init(struct em28x
"unable to register video device (error=%i).\n", ret);
goto unregister_dev;
}
+ kref_get(&v4l2->ref); /* put by video_unregister_device() */
/* Allocate and fill vbi video_device struct */
if (em28xx_vbi_supported(dev) == 1) {
--
^ permalink raw reply [flat|nested] 8+ messages in thread