syzbot


WARNING in __folio_mark_dirty (3)

Status: moderation: reported on 2025/08/10 17:42
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+c89af27ab247f308779b@syzkaller.appspotmail.com
First crash: 18d, last: 18d
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __folio_mark_dirty (2) gfs2 -1 C error 790989 52d 908d 29/29 fixed on 2025/07/16 19:06
upstream WARNING in __folio_mark_dirty gfs2 -1 C error 1791 912d 1396d 22/29 fixed on 2023/02/24 13:50
linux-6.1 WARNING in __folio_mark_dirty origin:upstream missing-backport -1 C 361682 now 900d 0/3 upstream: reported C repro on 2023/03/08 12:14
linux-6.6 WARNING in __folio_mark_dirty origin:lts-only -1 C 12640 24m 69d 0/2 upstream: reported C repro on 2025/06/16 17:15

Sample crash report:
loop0: detected capacity change from 0 to 2048
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
ext4 filesystem being mounted at /0/file0 supports timestamps until 2038-01-19 (0x7fffffff)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5370 at mm/page-writeback.c:2740 __folio_mark_dirty+0x100/0xec0 mm/page-writeback.c:2740
Modules linked in:
CPU: 0 UID: 0 PID: 5370 Comm: syz.0.0 Not tainted 6.16.0-syzkaller-11852-g479058002c32 #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:__folio_mark_dirty+0x100/0xec0 mm/page-writeback.c:2740
Code: 3c 08 00 74 08 48 89 df e8 6d b9 29 00 4c 8b 33 4c 89 f6 48 83 e6 08 31 ff e8 0c d5 c4 ff 49 83 e6 08 75 20 e8 21 d0 c4 ff 90 <0f> 0b 90 eb 1a e8 16 d0 c4 ff e9 bb 08 00 00 e8 0c d0 c4 ff 48 8b
RSP: 0018:ffffc9000d3e7a40 EFLAGS: 00010083
RAX: ffffffff81faeb3f RBX: ffffea000134bb40 RCX: 0000000000100000
RDX: ffffc9000e132000 RSI: 00000000000bbf45 RDI: 00000000000bbf46
RBP: 0000000000000001 R08: ffffea000134bb47 R09: 1ffffd4000269768
R10: dffffc0000000000 R11: fffff94000269769 R12: 0000000000000a02
R13: ffff8880433da168 R14: 0000000000000000 R15: ffff8880433da170
FS:  00007fe7ed5ed6c0(0000) GS:ffff88808d218000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555799b37c8 CR3: 000000003f192000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 block_dirty_folio+0x17a/0x1d0 fs/buffer.c:754
 unpin_user_pages_dirty_lock+0x37d/0x510 mm/gup.c:326
 process_vm_rw_single_vec mm/process_vm_access.c:127 [inline]
 process_vm_rw_core mm/process_vm_access.c:216 [inline]
 process_vm_rw+0x841/0xaf0 mm/process_vm_access.c:284
 __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
 __x64_sys_process_vm_writev+0xe0/0x100 mm/process_vm_access.c:299
 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: 0033:0x7fe7f118ebe9
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:00007fe7ed5ed038 EFLAGS: 00000246 ORIG_RAX: 0000000000000137
RAX: ffffffffffffffda RBX: 00007fe7f13b5fa0 RCX: 00007fe7f118ebe9
RDX: 0000000000000001 RSI: 0000200000c22000 RDI: 0000000000000004
RBP: 00007fe7f1211e19 R08: 0000000000000001 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7f13b6038 R14: 00007fe7f13b5fa0 R15: 00007ffef413ea78
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/06 17:39 upstream 479058002c32 4bd24a3e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __folio_mark_dirty
* Struck through repros no longer work on HEAD.