syzbot


WARNING in __btrfs_update_delayed_inode (4)

Status: upstream: reported on 2026/04/24 07:54
Subsystems: btrfs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+768687d6d7c96a124e24@syzkaller.appspotmail.com
First crash: 79d, last: 12d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
d8936ba7-6615-4c19-9488-c5da8b2e20e2 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in __btrfs_update_delayed_inode (4) 2026/05/19 01:17 2026/05/19 01:17 2026/05/19 01:57 9f74d39908454b73546eaf1b8211b48b66e5c0fe

			
		
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [btrfs?] WARNING in __btrfs_update_delayed_inode (4) 1 (2) 2026/04/24 14:13
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __btrfs_update_delayed_inode btrfs -1 2 1227d 1228d 0/29 auto-obsoleted due to no activity on 2023/06/27 15:17
upstream WARNING in __btrfs_update_delayed_inode (2) btrfs -1 2 481d 518d 0/29 auto-obsoleted due to no activity on 2025/06/22 17:49
upstream WARNING in __btrfs_update_delayed_inode (3) btrfs -1 1 207d 203d 0/29 auto-obsoleted due to no activity on 2026/03/23 08:26

Sample crash report:
IPv6: RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE
IPv6: NLM_F_CREATE should be set when creating new route
IPv6: NLM_F_CREATE should be set when creating new route
------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/delayed-inode.c:1027 at __btrfs_update_delayed_inode+0xcb2/0xd60 fs/btrfs/delayed-inode.c:1027, CPU#0: syz.0.0/5334
Modules linked in:
CPU: 0 UID: 0 PID: 5334 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 04/01/2014
RIP: 0010:__btrfs_update_delayed_inode+0xcb2/0xd60 fs/btrfs/delayed-inode.c:1027
Code: 47 83 7c 24 18 fb 74 39 83 7c 24 18 f4 75 40 e8 24 3d b6 fd eb 42 e8 1d 3d b6 fd eb 10 e8 16 3d b6 fd eb 09 e8 0f 3d b6 fd 90 <0f> 0b 90 44 89 e9 f7 d9 4c 8b 7c 24 28 4c 8b 74 24 30 e9 45 fd ff
RSP: 0018:ffffc9000e4e6e00 EFLAGS: 00010287
RAX: ffffffff841044c1 RBX: 00000000ffffffe4 RCX: 0000000000100000
RDX: ffffc90020001000 RSI: 0000000000012f80 RDI: 0000000000012f81
RBP: ffffc9000e4e6f30 R08: ffff88800019a540 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000002 R12: dffffc0000000000
R13: 00000000ffffffe4 R14: ffff888044217b00 R15: ffff8880425983c0
FS:  00007fb53245c6c0(0000) GS:ffff88808c81b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb532439ec0 CR3: 0000000012750000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1103 [inline]
 __btrfs_commit_inode_delayed_items+0x1d75/0x1ec0 fs/btrfs/delayed-inode.c:1127
 __btrfs_run_delayed_items+0x1d0/0x420 fs/btrfs/delayed-inode.c:1158
 btrfs_commit_transaction+0x844/0x30b0 fs/btrfs/transaction.c:2378
 btrfs_sync_file+0xec9/0x1400 fs/btrfs/file.c:1800
 generic_write_sync include/linux/fs.h:2661 [inline]
 btrfs_do_write_iter+0x640/0x790 fs/btrfs/file.c:1459
 iter_file_splice_write+0xa31/0x1240 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x101/0x160 fs/splice.c:1159
 splice_direct_to_actor+0x57b/0xcb0 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x195/0x290 fs/splice.c:1228
 do_sendfile+0x52e/0x7c0 fs/read_write.c:1371
 __do_sys_sendfile64 fs/read_write.c:1432 [inline]
 __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1418
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb53159ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb53245bfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fb531816090 RCX: 00007fb53159ce59
RDX: 0000000000000000 RSI: 000000000000000a RDI: 000000000000000c
RBP: 00007fb531632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000080000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb531816128 R14: 00007fb531816090 R15: 00007ffe49f90de8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/26 06:32 upstream 4edcdefd4083 7ff32d8b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __btrfs_update_delayed_inode
2026/04/20 07:47 upstream bea8d77e45a8 303e2802 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __btrfs_update_delayed_inode
* Struck through repros no longer work on HEAD.