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KASAN: use-after-free Read in v4l2_fh_open

Status: upstream: reported C repro on 2024/08/01 11:01
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+545d6080425f1f289ca9@syzkaller.appspotmail.com
First crash: 500d, last: 17h46m
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2024/08/02 upstream (ToT) c0ecd6388360 C [report] KASAN: slab-use-after-free Read in v4l2_fh_open
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in v4l2_fh_open usb media 19 C unreliable inconclusive 3116 2h45m 1763d 0/29 upstream: reported C repro on 2021/02/15 15:18
linux-6.1 KASAN: use-after-free Read in v4l2_fh_open origin:upstream 19 C 49 21d 479d 0/3 upstream: reported C repro on 2024/08/22 03:36
linux-6.6 KASAN: slab-use-after-free Read in v4l2_fh_open origin:upstream 19 C 29 3d12h 168d 0/2 upstream: reported C repro on 2025/06/29 09:48
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2025/05/16 14:23 13m retest repro linux-5.15.y report log
2025/05/16 14:23 1h17m retest repro linux-5.15.y report log
2025/05/16 14:23 10m retest repro linux-5.15.y report log
2024/11/26 20:18 14m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2024/09/06 00:23 1h29m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
==================================================================
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+0xc6/0x430 drivers/media/v4l2-core/v4l2-fh.c:63
Read of size 8 at addr ffff88805a534900 by task v4l_id/4472

CPU: 1 PID: 4472 Comm: v4l_id Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 v4l2_fh_init drivers/media/v4l2-core/v4l2-fh.c:25 [inline]
 v4l2_fh_open+0xc6/0x430 drivers/media/v4l2-core/v4l2-fh.c:63
 em28xx_v4l2_open+0x152/0x990 drivers/media/usb/em28xx/em28xx-video.c:2163
 v4l2_open+0x20b/0x360 drivers/media/v4l2-core/v4l2-dev.c:427
 chrdev_open+0x597/0x670 fs/char_dev.c:414
 do_dentry_open+0x7ff/0xf80 fs/open.c:826
 do_open fs/namei.c:3616 [inline]
 path_openat+0x2682/0x2f30 fs/namei.c:3750
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdb2f89c407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffc7e2da30 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fdb2f7ae880 RCX: 00007fdb2f89c407
RDX: 0000000000000000 RSI: 00007fffc7e2ef1d RDI: ffffffffffffff9c
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fffc7e2dc80 R14: 00007fdb3002a000 R15: 000055d961a284d8
 </TASK>

The buggy address belongs to the page:
page:ffffea0001694d00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a534
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001613108 ffffea000167a208 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x102800(GFP_NOWAIT|__GFP_NOWARN|__GFP_HARDWALL), pid 154, ts 91959334744, free_ts 91959341918
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 stack_depot_save+0x342/0x440 lib/stackdepot.c:302
 kasan_save_stack+0x4b/0x60 mm/kasan/common.c:40
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 kvfree_call_rcu+0x10a/0x7c0 kernel/rcu/tree.c:3600
 __hw_addr_del_entry net/core/dev_addr_lists.c:145 [inline]
 __hw_addr_del_ex+0x521/0x620 net/core/dev_addr_lists.c:194
 __hw_addr_unsync_one+0x59/0x270 net/core/dev_addr_lists.c:230
 __hw_addr_unsync net/core/dev_addr_lists.c:290 [inline]
 dev_mc_unsync+0x1a6/0x2d0 net/core/dev_addr_lists.c:984
 vlan_dev_stop+0x49/0x230 net/8021q/vlan_dev.c:298
 __dev_close_many+0x1c1/0x2a0 net/core/dev.c:1621
 dev_close_many+0x21f/0x400 net/core/dev.c:1646
 unregister_netdevice_many+0x472/0x18f0 net/core/dev.c:11110
 default_device_exit_batch+0x336/0x390 net/core/dev.c:11667
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 stack_depot_save+0x418/0x440 lib/stackdepot.c:335
 kasan_save_stack+0x4b/0x60 mm/kasan/common.c:40
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 kvfree_call_rcu+0x10a/0x7c0 kernel/rcu/tree.c:3600
 __hw_addr_del_entry net/core/dev_addr_lists.c:145 [inline]
 __hw_addr_del_ex+0x521/0x620 net/core/dev_addr_lists.c:194
 __hw_addr_unsync_one+0x59/0x270 net/core/dev_addr_lists.c:230
 __hw_addr_unsync net/core/dev_addr_lists.c:290 [inline]
 dev_mc_unsync+0x1a6/0x2d0 net/core/dev_addr_lists.c:984
 vlan_dev_stop+0x49/0x230 net/8021q/vlan_dev.c:298
 __dev_close_many+0x1c1/0x2a0 net/core/dev.c:1621
 dev_close_many+0x21f/0x400 net/core/dev.c:1646
 unregister_netdevice_many+0x472/0x18f0 net/core/dev.c:11110
 default_device_exit_batch+0x336/0x390 net/core/dev.c:11667
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310

Memory state around the buggy address:
 ffff88805a534800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805a534880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805a534900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88805a534980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805a534a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (185):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/27 00:12 linux-5.15.y ac56c046adf4 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/08/21 08:01 linux-5.15.y c79648372d02 0b9605c8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/08/21 07:16 linux-5.15.y c79648372d02 0b9605c8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/06/01 01:32 linux-5.15.y 98f47d0e9b8c 3d2f584d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/03/14 13:30 linux-5.15.y 0c935c049b5c e2826670 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/01 14:37 linux-5.15.y 0a51d2d4527b 68914665 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/08/02 07:45 linux-5.15.y 7e89efd3ae1c 1e9c4cf3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/14 05:18 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/13 01:51 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/10 14:19 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/07 06:31 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/06 09:38 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/03 15:50 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/02 21:01 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/12/02 07:30 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/30 10:43 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/29 20:44 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/28 18:42 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/25 07:30 linux-5.15.y cc5ec8769306 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/21 12:39 linux-5.15.y cc5ec8769306 280ea308 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/20 21:44 linux-5.15.y cc5ec8769306 2cc4c24a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/18 04:57 linux-5.15.y cc5ec8769306 ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/12 12:41 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/11 06:39 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/10 01:17 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/09 19:09 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/07 12:56 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/07 04:57 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/02 16:26 linux-5.15.y cc5ec8769306 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/10/27 19:31 linux-5.15.y ac56c046adf4 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/10/24 20:28 linux-5.15.y ac56c046adf4 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/10/24 16:43 linux-5.15.y ac56c046adf4 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/10/24 00:23 linux-5.15.y ac56c046adf4 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/10/17 14:08 linux-5.15.y 29e53a5b1c4f 7adf5298 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/10/13 15:48 linux-5.15.y 29e53a5b1c4f b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/10/06 15:38 linux-5.15.y 29e53a5b1c4f 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/23 22:20 linux-5.15.y 43bb85222e53 e667a34f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/22 18:00 linux-5.15.y 43bb85222e53 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/22 06:49 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/21 15:19 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/21 07:24 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/19 18:24 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/19 07:25 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/19 06:23 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/18 16:38 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/18 06:49 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/17 16:57 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/17 14:59 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/15 06:41 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/14 21:42 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/12 00:10 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/07 12:16 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/09/04 18:20 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/08/01 11:00 linux-5.15.y 7e89efd3ae1c 1e9c4cf3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/11/16 12:34 linux-5.15.y cc5ec8769306 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: out-of-bounds Read in v4l2_fh_open
* Struck through repros no longer work on HEAD.