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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: 179d, last: 22h41m
▶ ▼ 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 (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in v4l2_fh_open usb media C unreliable inconclusive 833 1d13h 1442d 0/28 upstream: reported C repro on 2021/02/15 15:18
linux-6.1 KASAN: use-after-free Read in v4l2_fh_open 6 29d 158d 0/3 upstream: reported on 2024/08/22 03:36
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
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+0xc7/0x430 drivers/media/v4l2-core/v4l2-fh.c:63
Read of size 8 at addr ffff888022d38900 by task v4l_id/5812

CPU: 0 PID: 5812 Comm: v4l_id Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 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+0x15d/0xa10 drivers/media/usb/em28xx/em28xx-video.c:2163
 v4l2_open+0x228/0x360 drivers/media/v4l2-core/v4l2-dev.c:427
 chrdev_open+0x54a/0x630 fs/char_dev.c:414
 do_dentry_open+0x807/0xfb0 fs/open.c:826
 do_open fs/namei.c:3608 [inline]
 path_openat+0x2705/0x2f20 fs/namei.c:3742
 do_filp_open+0x21c/0x460 fs/namei.c:3769
 do_sys_openat2+0x13b/0x4f0 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+0x243/0x290 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa0ae5b29a4
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:00007ffc827b8ca0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffc827b8eb8 RCX: 00007fa0ae5b29a4
RDX: 0000000000000000 RSI: 00007ffc827b9f1b RDI: 00000000ffffff9c
RBP: 00007ffc827b9f1b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc827b8ed0 R14: 0000560569995670 R15: 00007fa0ae9fba80
 </TASK>

The buggy address belongs to the page:
page:ffffea00008b4e00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22d38
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001f10b08 ffff8880b8f409b0 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 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 2350, ts 246030411375, free_ts 246157471874
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5464
 kmalloc_order+0x41/0x150 mm/slab_common.c:966
 kmalloc_order_trace+0x15/0xe0 mm/slab_common.c:982
 kmalloc_large include/linux/slab.h:520 [inline]
 kmalloc include/linux/slab.h:584 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 em28xx_v4l2_init+0xe2/0x2d50 drivers/media/usb/em28xx/em28xx-video.c:2542
 em28xx_init_extension+0x11b/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1126
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
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+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 free_nonslab_page+0xe4/0x150 mm/slub.c:3535
 kfree+0x1cf/0x270 mm/slub.c:4556
 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2128 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_v4l2_init+0x15d7/0x2d50 drivers/media/usb/em28xx/em28xx-video.c:2911
 em28xx_init_extension+0x11b/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1126
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff888022d38800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888022d38880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888022d38900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888022d38980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888022d38a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (37):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2025/01/27 04:42 linux-5.15.y 003148680b79 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/26 05:27 linux-5.15.y 003148680b79 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/25 20:14 linux-5.15.y 003148680b79 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/25 08:15 linux-5.15.y 003148680b79 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/23 21:30 linux-5.15.y 003148680b79 521b0ce3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/19 05:21 linux-5.15.y 4735586da88e f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/12 14:47 linux-5.15.y 4735586da88e 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/08 12:18 linux-5.15.y 91786f140358 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/07 12:00 linux-5.15.y 91786f140358 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2025/01/05 10:12 linux-5.15.y 91786f140358 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/28 18:03 linux-5.15.y 91786f140358 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/28 17:42 linux-5.15.y 91786f140358 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/25 21:07 linux-5.15.y 91786f140358 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/22 15:07 linux-5.15.y 91786f140358 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/12 04:49 linux-5.15.y 0a51d2d4527b 6f1b0fa8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/06 21:53 linux-5.15.y 0a51d2d4527b 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/12/01 03:54 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/11/12 20:12 linux-5.15.y 3c17fc483905 62026c85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/11/05 11:30 linux-5.15.y 72244eab0dad da38b4c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/11/02 02:24 linux-5.15.y 72244eab0dad f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/10/25 11:41 linux-5.15.y 74cdd62cb470 045e728d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/10/10 02:21 linux-5.15.y 3a5928702e71 0278d004 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/10/10 02:21 linux-5.15.y 3a5928702e71 0278d004 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/10/02 04:33 linux-5.15.y 3a5928702e71 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/10/02 04:17 linux-5.15.y 3a5928702e71 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/10/01 11:24 linux-5.15.y 3a5928702e71 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/09/20 13:14 linux-5.15.y 3a5928702e71 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/09/20 05:33 linux-5.15.y 3a5928702e71 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/09/19 11:05 linux-5.15.y 3a5928702e71 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/09/15 06:15 linux-5.15.y 3a5928702e71 08d8a733 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/09/09 12:13 linux-5.15.y 14e468424d3e 073f8be2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/09/07 04:59 linux-5.15.y 14e468424d3e 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in v4l2_fh_open
2024/08/02 06:14 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
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
2025/01/10 09:09 linux-5.15.y 4735586da88e 67d7ec0a .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.