syzbot


WARNING in btrfs_lookup_extent_info (2)

Status: upstream: reported on 2025/08/01 18:56
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+c035bce0effd1de39e05@syzkaller.appspotmail.com
First crash: 89d, last: 31d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [btrfs?] WARNING in btrfs_lookup_extent_info (2) 1 (2) 2025/08/01 21:48
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in btrfs_lookup_extent_info btrfs -1 2 270d 348d 0/29 auto-obsoleted due to no activity on 2025/05/08 17:12

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5359 at fs/btrfs/extent-tree.c:209 btrfs_lookup_extent_info+0xc4e/0xf00 fs/btrfs/extent-tree.c:209
Modules linked in:
CPU: 0 UID: 0 PID: 5359 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:btrfs_lookup_extent_info+0xc4e/0xf00 fs/btrfs/extent-tree.c:209
Code: f8 76 fd fd eb 77 e8 91 08 ba 07 89 c3 31 ff 89 c6 e8 26 7b fd fd 85 db 75 28 e8 dd 76 fd fd e9 34 01 00 00 e8 d3 76 fd fd 90 <0f> 0b 90 e9 e9 fd ff ff 80 3d 1a 4b eb 0b 01 75 1e e8 bc 76 fd fd
RSP: 0018:ffffc9000d4ff220 EFLAGS: 00010293
RAX: ffffffff83c2466d RBX: ffff8880526d13b0 RCX: ffff888000df8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000d4ff380 R08: ffff8880526d13b3 R09: 1ffff1100a4da276
R10: dffffc0000000000 R11: ffffed100a4da277 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc9000d4ff440 R15: ffff888054143e04
FS:  00007f5565e6c6c0(0000) GS:ffff88808d007000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d76050b168 CR3: 0000000043630000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 update_ref_for_cow+0x991/0x13c0 fs/btrfs/ctree.c:384
 btrfs_force_cow_block+0xa0d/0x2460 fs/btrfs/ctree.c:538
 btrfs_cow_block+0x40a/0x9a0 fs/btrfs/ctree.c:699
 btrfs_search_slot+0xd11/0x2b90 fs/btrfs/ctree.c:2097
 drop_verity_items+0x1ad/0x4a0 fs/btrfs/verity.c:137
 btrfs_drop_verity_items+0x1b/0x60 fs/btrfs/verity.c:191
 btrfs_orphan_cleanup+0x396/0xca0 fs/btrfs/inode.c:3690
 create_snapshot+0x84c/0xba0 fs/btrfs/ioctl.c:790
 btrfs_mksubvol+0x545/0x6d0 fs/btrfs/ioctl.c:934
 btrfs_mksnapshot+0xab/0xf0 fs/btrfs/ioctl.c:978
 __btrfs_ioctl_snap_create+0x520/0x730 fs/btrfs/ioctl.c:1242
 btrfs_ioctl_snap_create_v2+0x1f8/0x3b0 fs/btrfs/ioctl.c:1322
 btrfs_ioctl+0xa62/0xd00 fs/btrfs/ioctl.c:-1
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5564f8eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5565e6c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f55651e6090 RCX: 00007f5564f8eec9
RDX: 0000200000000b00 RSI: 0000000050009417 RDI: 0000000000000004
RBP: 00007f5565011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55651e6128 R14: 00007f55651e6090 R15: 00007ffcaabb3b58
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/24 06:23 upstream cec1e6e5d1ab 0abd0691 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in btrfs_lookup_extent_info
2025/07/28 18:53 upstream 038d61fd6422 6654ea9c .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in btrfs_lookup_extent_info
* Struck through repros no longer work on HEAD.