WARNING in filemap_unaccount_folio (3)

Status: upstream: reported on 2026/05/02 00:00
Reported-by: syzbot+ff5a0dfc039e9b3164cf@syzkaller.appspotmail.com
First crash: 108d, last: 16d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in filemap_unaccount_folio -1 1 860d 860d 0/3 auto-obsoleted due to no activity on 2024/07/18 19:10
upstream WARNING in filemap_unaccount_folio nilfs -1 syz, C inconclusive 13 783d 818d 26/29 fixed on 2024/08/06 11:02
linux-6.1 WARNING in filemap_unaccount_folio (2) -1 1 425d 425d 0/3 auto-obsoleted due to no activity on 2025/09/26 12:13

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 9054 at mm/filemap.c:208 filemap_unaccount_folio+0x49b/0xa00 mm/filemap.c:207
Modules linked in:
CPU: 1 PID: 9054 Comm: syz.3.1270 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:filemap_unaccount_folio+0x49b/0xa00 mm/filemap.c:207
Code: 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 8e ff d6 ff 4c 8b 24 24 43 80 3c 2f 00 0f 85 25 ff ff ff e9 28 ff ff ff e8 75 ff d6 ff <0f> 0b 43 80 3c 2e 00 74 08 4c 89 e7 e8 24 2c 28 00 49 8b 3c 24 e8
RSP: 0018:ffffc90003b5f800 EFLAGS: 00010083
RAX: ffffffff81ab2eab RBX: ffffea000190e0c0 RCX: 0000000000080000
RDX: ffffc9000ea51000 RSI: 000000000000f550 RDI: 000000000000f551
RBP: 0000000000000003 R08: ffffea000190e0c7 R09: 1ffffd4000321c18
R10: dffffc0000000000 R11: fffff94000321c19 R12: ffff88807a8f8800
R13: dffffc0000000000 R14: 1ffff1100f51f100 R15: 0000000000000000
FS:  00007f0d8dc8f6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb14d7cca90 CR3: 000000001db0d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 delete_from_page_cache_batch+0x153/0xa80 mm/filemap.c:332
 truncate_inode_pages_range+0x2d5/0x10b0 mm/truncate.c:394
 kill_bdev block/bdev.c:76 [inline]
 set_blocksize+0x2e4/0x470 block/bdev.c:164
 swsusp_check+0xf6/0x450 kernel/power/swap.c:1529
 software_resume+0x10e/0x6a0 kernel/power/hibernate.c:1000
 resume_store+0xf7/0x1a0 kernel/power/hibernate.c:1205
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0d8cd9e019
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:00007f0d8dc8f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0d8d025fa0 RCX: 00007f0d8cd9e019
RDX: 000000000000fdef RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007f0d8ce3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d8d026038 R14: 00007f0d8d025fa0 R15: 00007ffe7cd37268
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/01 10:32 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in filemap_unaccount_folio
2026/05/02 00:00 linux-6.1.y 4931e0e1673d 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in filemap_unaccount_folio
* Struck through repros no longer work on HEAD.