WARNING in blkdev_flush_mapping

Status: upstream: reported C repro on 2026/08/04 22:22
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+ffcc586d4c44d8a17e46@syzkaller.appspotmail.com
First crash: 48d, last: 4d12h
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/08/16 linux-6.6.y (ToT) d27334b2888c C [report] WARNING in blkdev_flush_mapping
2026/08/16 upstream (ToT) 3eb40771c00a C Didn't crash

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5796 at block/bdev.c:643 blkdev_flush_mapping+0xac/0x290 block/bdev.c:643
Modules linked in:
CPU: 1 PID: 5796 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:blkdev_flush_mapping+0xac/0x290 block/bdev.c:643
Code: 42 80 3c 28 00 74 08 4c 89 f7 e8 8f 32 cc fd 49 8b 3e 48 ba ff ff ff ff ff ff ff 7f 31 f6 e8 5b bf a1 fd eb 11 e8 44 af 73 fd <0f> 0b 48 85 db 75 9f e8 38 af 73 fd 48 89 1c 24 4c 8d b3 80 00 00
RSP: 0018:ffffc900045bfda0 EFLAGS: 00010293
RAX: ffffffff8413c2dc RBX: ffff888148c869c0 RCX: ffff888079433c00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffff888148c869fb R09: 1ffff11029190d3f
R10: dffffc0000000000 R11: ffffed1029190d40 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888148c86af4 R15: ffff888148c869f8
FS:  00007f6e70559880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e6ff909c0 CR3: 00000000240cb000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 blkdev_put_whole block/bdev.c:676 [inline]
 blkdev_put+0x49a/0x7a0 block/bdev.c:954
 blkdev_release+0x84/0x90 block/fops.c:604
 __fput+0x221/0x940 fs/file_table.c:418
 __do_sys_close fs/open.c:1574 [inline]
 __se_sys_close+0x15c/0x1e0 fs/open.c:1559
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6e6fea7407
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:00007ffe3e9f44f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f6e70559880 RCX: 00007f6e6fea7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f6e705596e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 00005568bfe6e410 R14: 0000000000000008 R15: 00005568bfe7b970
 </TASK>

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/11 10:21 linux-6.6.y d27334b2888c 508909ea .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/09/18 01:29 linux-6.6.y 79643295eba1 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/09/18 01:29 linux-6.6.y 79643295eba1 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/09/09 09:50 linux-6.6.y 8b73de7da85f 8387c273 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/09/09 08:34 linux-6.6.y 8b73de7da85f 8387c273 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/09/09 08:34 linux-6.6.y 8b73de7da85f 8387c273 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/09/08 20:13 linux-6.6.y 8b73de7da85f 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/09/02 05:47 linux-6.6.y a4a971135a2f 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/25 23:16 linux-6.6.y dc6160265ffc a9a1fc32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/11 04:42 linux-6.6.y d27334b2888c 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/11 04:42 linux-6.6.y d27334b2888c 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/10 04:17 linux-6.6.y d27334b2888c 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/10 04:17 linux-6.6.y d27334b2888c 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/07 04:56 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/07 04:56 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/07 04:56 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/04 23:30 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/04 23:29 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/04 23:29 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/04 22:22 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
2026/08/04 22:21 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in blkdev_flush_mapping
* Struck through repros no longer work on HEAD.