syzbot


kernel BUG in filemap_unaccount_folio

Status: upstream: reported on 2025/06/24 02:03
Reported-by: syzbot+344dc92e07dbfaf6fe78@syzkaller.appspotmail.com
First crash: 7h35m, last: 7h35m
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in filemap_unaccount_folio mm C done error 386 2d08h 656d 0/29 upstream: reported C repro on 2023/09/06 18:51
linux-6.1 kernel BUG in filemap_unaccount_folio origin:upstream missing-backport C done 927 3h07m 559d 0/3 upstream: reported C repro on 2023/12/13 08:56
upstream kernel BUG in __filemap_get_folio kernel C done 814 990d 1160d 22/29 fixed on 2023/02/24 13:50

Sample crash report:
 reclaim_folio_list+0xe4/0x380 mm/vmscan.c:2788
 reclaim_pages+0x564/0x680 mm/vmscan.c:2824
 madvise_cold_or_pageout_pte_range+0x1812/0x2050 mm/madvise.c:430
 walk_pmd_range mm/pagewalk.c:143 [inline]
 walk_pud_range mm/pagewalk.c:221 [inline]
 walk_p4d_range mm/pagewalk.c:256 [inline]
 walk_pgd_range+0xc4c/0x1820 mm/pagewalk.c:293
 __walk_page_range+0x134/0x5b0 mm/pagewalk.c:395
 walk_page_range+0x345/0x510 mm/pagewalk.c:521
 madvise_pageout_page_range mm/madvise.c:592 [inline]
 madvise_pageout mm/madvise.c:619 [inline]
 madvise_vma_behavior mm/madvise.c:1037 [inline]
 madvise_walk_vmas mm/madvise.c:1266 [inline]
 do_madvise+0x23cf/0x3710 mm/madvise.c:1446
 __do_sys_madvise mm/madvise.c:1459 [inline]
 __se_sys_madvise mm/madvise.c:1457 [inline]
 __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1457
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page has been migrated, last migrate reason: mempolicy_mbind
------------[ cut here ]------------
kernel BUG at mm/filemap.c:155!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 20096 Comm: syz.6.2642 Not tainted 6.6.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:filemap_unaccount_folio+0x704/0xc60 mm/filemap.c:155
Code: 48 25 ff 0f 00 00 0f 84 ec 00 00 00 e8 05 50 d1 ff e9 74 f9 ff ff e8 fb 4f d1 ff 48 89 df 48 c7 c6 e0 2b b3 8a e8 ac 75 12 00 <0f> 0b e8 e5 4f d1 ff 48 89 df 48 c7 c6 60 31 b3 8a e8 96 75 12 00
RSP: 0018:ffffc900044af3b8 EFLAGS: 00010046
RAX: 5e4f0ea49064ff00 RBX: ffffea0001660000 RCX: 5e4f0ea49064ff00
RDX: 0000000000000005 RSI: ffffffff8aaac440 RDI: ffffffff8afc6900
RBP: ffffc900044af518 R08: ffffffff8e49ab2f R09: 1ffffffff1c93565
R10: dffffc0000000000 R11: fffffbfff1c93566 R12: 0000000000000040
R13: 1ffffd40002cc000 R14: 1ffffd40002cc001 R15: ffffea0001660008
FS:  00007ffa88f5f6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc59af5c000 CR3: 0000000020b66000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __filemap_remove_folio+0xc4/0x7f0 mm/filemap.c:224
 filemap_remove_folio+0xf1/0x2c0 mm/filemap.c:257
 hugetlb_delete_from_page_cache fs/hugetlbfs/inode.c:433 [inline]
 remove_inode_single_folio fs/hugetlbfs/inode.c:638 [inline]
 remove_inode_hugepages+0x5dc/0x1870 fs/hugetlbfs/inode.c:696
 hugetlbfs_punch_hole fs/hugetlbfs/inode.c:816 [inline]
 hugetlbfs_fallocate+0xd45/0x1090 fs/hugetlbfs/inode.c:842
 vfs_fallocate+0x58e/0x700 fs/open.c:324
 madvise_remove mm/madvise.c:1007 [inline]
 madvise_vma_behavior mm/madvise.c:1031 [inline]
 madvise_walk_vmas mm/madvise.c:1266 [inline]
 do_madvise+0x15fe/0x3710 mm/madvise.c:1446
 __do_sys_madvise mm/madvise.c:1459 [inline]
 __se_sys_madvise mm/madvise.c:1457 [inline]
 __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1457
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ffa8818e929
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:00007ffa88f5f038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007ffa883b6240 RCX: 00007ffa8818e929
RDX: 0000000000000009 RSI: 0000000000600002 RDI: 0000200000000000
RBP: 00007ffa88210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffa883b6240 R15: 00007fff96ae67d8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:filemap_unaccount_folio+0x704/0xc60 mm/filemap.c:155
Code: 48 25 ff 0f 00 00 0f 84 ec 00 00 00 e8 05 50 d1 ff e9 74 f9 ff ff e8 fb 4f d1 ff 48 89 df 48 c7 c6 e0 2b b3 8a e8 ac 75 12 00 <0f> 0b e8 e5 4f d1 ff 48 89 df 48 c7 c6 60 31 b3 8a e8 96 75 12 00
RSP: 0018:ffffc900044af3b8 EFLAGS: 00010046
RAX: 5e4f0ea49064ff00 RBX: ffffea0001660000 RCX: 5e4f0ea49064ff00
RDX: 0000000000000005 RSI: ffffffff8aaac440 RDI: ffffffff8afc6900
RBP: ffffc900044af518 R08: ffffffff8e49ab2f R09: 1ffffffff1c93565
R10: dffffc0000000000 R11: fffffbfff1c93566 R12: 0000000000000040
R13: 1ffffd40002cc000 R14: 1ffffd40002cc001 R15: ffffea0001660008
FS:  00007ffa88f5f6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc59af5c000 CR3: 0000000020b66000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/24 02:02 linux-6.6.y 6282921b6825 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in filemap_unaccount_folio
* Struck through repros no longer work on HEAD.