syzbot


KCSAN: data-race in __filemap_remove_folio / folio_mapping (2)

Status: upstream: reported on 2023/04/24 07:19
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+606f94dfeaaa45124c90@syzkaller.appspotmail.com
First crash: 1283d, last: 19h15m
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
25562d31-60b8-4862-87af-97ce4f3ef817 repro KCSAN: data-race in __filemap_remove_folio / folio_mapping (2) 2026/03/10 13:50 2026/03/12 16:01 2026/03/12 16:15 86914af9098a80da53c3c5d46be980c572ee29f8
10ce9772-673a-4cf2-916e-4c32693bd07c assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in __filemap_remove_folio / folio_mapping (2) 2026/01/14 20:44 2026/01/14 20:44 2026/01/14 20:47 a9d6a79219801d2130df3b1a792c57f0e5428e9f
Discussions (19)
Title Replies (including bot) Last reply
[PATCH] mm: fix data race in __filemap_remove_folio / folio_mapping 3 (3) 2026/03/23 10:47
[syzbot] Monthly mm report (Mar 2026) 0 (1) 2026/03/23 08:58
[syzbot] Monthly mm report (Feb 2026) 0 (1) 2026/02/18 13:20
[syzbot] Monthly mm report (Jan 2026) 0 (1) 2026/01/19 08:18
[syzbot] Monthly mm report (Dec 2025) 0 (1) 2025/12/18 10:06
[syzbot] Monthly mm report (Sep 2025) 0 (1) 2025/09/15 06:54
[syzbot] Monthly mm report (Aug 2025) 0 (1) 2025/08/14 12:42
[syzbot] Monthly mm report (Jul 2025) 0 (1) 2025/07/14 07:23
[syzbot] Monthly mm report (Jun 2025) 0 (1) 2025/06/13 12:25
[syzbot] Monthly mm report (May 2025) 0 (1) 2025/05/12 13:34
[syzbot] Monthly mm report (Apr 2025) 0 (1) 2025/04/09 07:11
[syzbot] Monthly mm report (Oct 2024) 0 (1) 2024/10/03 09:02
[syzbot] Monthly mm report (Sep 2024) 0 (1) 2024/09/02 08:17
[syzbot] [fs?] [mm?] KCSAN: data-race in __filemap_remove_folio / folio_mapping (2) 6 (8) 2024/04/18 04:27
[syzbot] Monthly mm report (Feb 2024) 0 (1) 2024/02/17 20:23
[syzbot] Monthly mm report (Nov 2023) 0 (1) 2023/11/15 03:00
[syzbot] Monthly mm report (Sep 2023) 0 (1) 2023/09/11 10:07
[syzbot] Monthly xfs report (Aug 2023) 0 (1) 2023/08/07 08:36
[syzbot] Monthly xfs report (Jun 2023) 0 (1) 2023/06/07 09:24
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __filemap_remove_folio / folio_mapping block 6 42 1491d 1554d 0/29 auto-closed as invalid on 2022/04/21 14:11

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __filemap_remove_folio / folio_mapping

write to 0xffffea0005594798 of 8 bytes by task 17182 on cpu 0:
 page_cache_delete mm/filemap.c:145 [inline]
 __filemap_remove_folio+0x201/0x2e0 mm/filemap.c:228
 filemap_remove_folio+0x6d/0x1d0 mm/filemap.c:257
 truncate_inode_folio+0x42/0x50 mm/truncate.c:176
 shmem_undo_range+0x26d/0xb10 mm/shmem.c:1145
 shmem_truncate_range mm/shmem.c:1277 [inline]
 shmem_evict_inode+0x12e/0x540 mm/shmem.c:1407
 evict+0x2af/0x510 fs/inode.c:841
 iput_final fs/inode.c:1960 [inline]
 iput+0x41a/0x580 fs/inode.c:2009
 dentry_unlink_inode+0x24f/0x260 fs/dcache.c:467
 __dentry_kill+0x13f/0x460 fs/dcache.c:670
 finish_dput+0x2b/0x200 fs/dcache.c:879
 dput+0x52/0x60 fs/dcache.c:928
 __fput+0x444/0x630 fs/file_table.c:518
 ____fput+0x1c/0x30 fs/file_table.c:538
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x4ae/0x1530 kernel/exit.c:977
 do_group_exit+0xfe/0x140 kernel/exit.c:1119
 get_signal+0xe30/0xf20 kernel/signal.c:3039
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline]
 irqentry_exit+0x140/0x5b0 kernel/entry/common.c:162
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

read to 0xffffea0005594798 of 8 bytes by task 17415 on cpu 1:
 folio_mapping+0xa1/0xe0 mm/util.c:732
 folio_evictable mm/internal.h:585 [inline]
 sort_folio mm/vmscan.c:4463 [inline]
 scan_folios mm/vmscan.c:4590 [inline]
 isolate_folios mm/vmscan.c:4682 [inline]
 evict_folios+0xdbe/0x33b0 mm/vmscan.c:4712
 try_to_shrink_lruvec+0x81b/0xbf0 mm/vmscan.c:4885
 lru_gen_shrink_lruvec mm/vmscan.c:5034 [inline]
 shrink_lruvec+0x265/0x1b70 mm/vmscan.c:5793
 shrink_node_memcgs mm/vmscan.c:6032 [inline]
 shrink_node+0x699/0x2100 mm/vmscan.c:6076
 shrink_zones mm/vmscan.c:6315 [inline]
 do_try_to_free_pages+0x408/0xc90 mm/vmscan.c:6377
 try_to_free_mem_cgroup_pages+0x201/0x420 mm/vmscan.c:6699
 try_charge_memcg+0x373/0xa10 mm/memcontrol.c:2439
 obj_cgroup_charge_pages mm/memcontrol.c:2882 [inline]
 __memcg_kmem_charge_page+0x139/0x2b0 mm/memcontrol.c:2926
 __alloc_frozen_pages_noprof+0x18a/0x350 mm/page_alloc.c:5245
 alloc_pages_mpol+0xb3/0x260 mm/mempolicy.c:2490
 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline]
 alloc_pages_noprof+0x8f/0x140 mm/mempolicy.c:2581
 vm_area_alloc_pages mm/vmalloc.c:3728 [inline]
 __vmalloc_area_node mm/vmalloc.c:3878 [inline]
 __vmalloc_node_range_noprof+0xaed/0x11c0 mm/vmalloc.c:4064
 __kvmalloc_node_noprof+0x3d4/0x640 mm/slub.c:6856
 futex_hash_allocate+0x190/0x9a0 kernel/futex/core.c:1815
 futex_hash_prctl+0xd8/0xf0 kernel/futex/core.c:1961
 __do_sys_prctl kernel/sys.c:2885 [inline]
 __se_sys_prctl+0x4f4/0x1400 kernel/sys.c:2534
 __x64_sys_prctl+0x67/0x80 kernel/sys.c:2534
 x64_sys_call+0x2533/0x3020 arch/x86/include/generated/asm/syscalls_64.h:158
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88811bc51f70 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 17415 Comm: syz.0.6822 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
==================================================================

Crashes (971):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/16 01:04 upstream aec2f682d47c df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/15 04:39 upstream 508fed679541 e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/14 16:20 upstream d60bc1401583 362d1323 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/13 23:02 upstream 26ff969926a0 1a086e7c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/09 20:34 upstream 8b02520ec5f7 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/08 13:49 upstream 3036cd0d3328 d9b7f621 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/07 23:11 upstream 3036cd0d3328 2c961e87 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/07 15:31 upstream bfe62a454542 628666c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/06 20:59 upstream bfe62a454542 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/06 10:53 upstream 591cd656a1bf 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/05 18:23 upstream 1791c390149f 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/04 21:40 upstream 7ca6d1cfec80 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/04 11:40 upstream 631919fb12fe 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/03 18:57 upstream d8a9a4b11a13 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/03 02:17 upstream 5619b098e2fb 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/04/01 20:41 upstream dbf00d8d23b4 9a1f7828 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/31 14:54 upstream d0c3bcd5b897 aeea1c72 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/31 00:11 upstream d0c3bcd5b897 d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/30 16:35 upstream 7aaa8047eafd dcaebc52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/29 18:02 upstream a3d97d1d3fa6 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/25 16:14 upstream bbeb83d3182a 8ee77f7d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/24 23:38 upstream 24f9515de877 74e70d19 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/24 06:09 upstream c369299895a5 baf8bf12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/23 13:56 upstream c369299895a5 4933dba2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/23 00:20 upstream ec69c9e88315 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/19 13:59 upstream 8a30aeb0d1b4 bd6dcb30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/18 17:14 upstream a989fde763f4 0199f9a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/18 02:26 upstream f0caa1d49cc0 c8810548 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/17 17:22 upstream 2d1373e4246d c01bca74 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/17 01:18 upstream 2d1373e4246d 0737c18f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/12 00:48 upstream b29fb8829bff 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/11 16:23 upstream b29fb8829bff 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/10 03:34 upstream 1f318b96cc84 6972f302 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/09 17:25 upstream 1f318b96cc84 176bead5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/08 22:30 upstream 014441d1e4b2 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/07 19:55 upstream 4ae12d8bd9a8 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/06 18:10 upstream 5ee8dbf54602 41d8037d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/04 11:29 upstream 0031c06807cf e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/03 18:15 upstream af4e9ef3d784 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/03 05:01 upstream af4e9ef3d784 28b83e23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/03/01 16:28 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/02/28 11:35 upstream 4d349ee5c778 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/02/27 19:56 upstream a75cb869a8cc 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2026/01/14 08:56 upstream c537e12daeec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2023/04/23 07:32 upstream 622322f53c6d 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2023/04/16 16:53 upstream 3e7bb4f24617 ec410564 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2023/04/10 04:10 upstream 09a9639e56c0 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
2022/10/11 17:24 upstream 60bb8154d1d7 02b6492e .config console log report info [disk image] [vmlinux] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_remove_folio / folio_mapping
* Struck through repros no longer work on HEAD.