syzbot


KCSAN: data-race in __xa_clear_mark / xas_find_marked (2)

Status: moderation: reported on 2021/06/26 18:58
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+03743c59b799c7b55cd4@syzkaller.appspotmail.com
First crash: 1686d, last: 7h53m
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __xa_clear_mark / xas_find_marked mm fs 6 558 1686d 1987d 0/29 closed as invalid on 2021/06/07 13:50

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __xa_clear_mark / xas_find_marked

write to 0xffff88811bd77814 of 4 bytes by interrupt on cpu 0:
 xa_mark_clear lib/xarray.c:77 [inline]
 xas_clear_mark lib/xarray.c:932 [inline]
 __xa_clear_mark+0x1c6/0x1e0 lib/xarray.c:2100
 __folio_end_writeback+0xf4/0x360 mm/page-writeback.c:2992
 folio_end_writeback_no_dropbehind+0x6d/0x1d0 mm/filemap.c:1661
 folio_end_writeback+0x1c/0x70 mm/filemap.c:1687
 end_buffer_async_write+0x156/0x1f0 fs/buffer.c:419
 end_bio_bh_io_sync+0x79/0xa0 fs/buffer.c:2776
 bio_endio+0x37a/0x410 block/bio.c:1675
 blk_update_request+0x338/0x730 block/blk-mq.c:1007
 blk_mq_end_request+0x26/0x50 block/blk-mq.c:1169
 lo_complete_rq+0x98/0x140 drivers/block/loop.c:314
 blk_complete_reqs block/blk-mq.c:1244 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1249
 handle_softirqs+0xb9/0x280 kernel/softirq.c:622
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:1063
 smpboot_thread_fn+0x32a/0x510 kernel/smpboot.c:160
 kthread+0x488/0x510 kernel/kthread.c:463
 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read to 0xffff88811bd77814 of 4 bytes by task 11634 on cpu 1:
 xa_marked include/linux/xarray.h:424 [inline]
 xas_find_marked+0x5d7/0x620 lib/xarray.c:1483
 find_get_entry+0x5d/0x380 mm/filemap.c:2064
 filemap_get_folios_tag+0xb6/0x230 mm/filemap.c:2332
 __filemap_fdatawait_range mm/filemap.c:523 [inline]
 file_write_and_wait_range+0x20c/0x2f0 mm/filemap.c:789
 __generic_file_fsync+0x46/0x160 fs/libfs.c:1558
 fat_file_fsync+0x49/0x100 fs/fat/file.c:191
 vfs_fsync_range+0x10d/0x130 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2616 [inline]
 generic_file_write_iter+0x1ba/0x310 mm/filemap.c:4461
 iter_file_splice_write+0x6bc/0xa80 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1161
 splice_direct_to_actor+0x311/0x670 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2db1/0x3000 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0e000021 -> 0x04000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11634 Comm: syz.0.3083 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================
==================================================================
BUG: KCSAN: data-race in __writeback_single_inode / xas_set_mark

write to 0xffff88811bd77814 of 4 bytes by task 11631 on cpu 1:
 xa_mark_set lib/xarray.c:71 [inline]
 xas_set_mark+0x12b/0x140 lib/xarray.c:900
 __folio_start_writeback+0x17b/0x370 mm/page-writeback.c:3038
 __block_write_full_folio+0x53a/0x8f0 fs/buffer.c:1928
 block_write_full_folio+0x2c1/0x2e0 fs/buffer.c:-1
 mpage_write_folio fs/mpage.c:641 [inline]
 mpage_writepages+0x710/0x1310 fs/mpage.c:670
 fat_writepages+0x24/0x30 fs/fat/inode.c:200
 do_writepages+0x1c6/0x310 mm/page-writeback.c:2598
 filemap_writeback mm/filemap.c:387 [inline]
 filemap_fdatawrite_range mm/filemap.c:412 [inline]
 file_write_and_wait_range+0x178/0x2f0 mm/filemap.c:786
 __generic_file_fsync+0x46/0x160 fs/libfs.c:1558
 fat_file_fsync+0x49/0x100 fs/fat/file.c:191
 vfs_fsync_range+0x10d/0x130 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2616 [inline]
 generic_file_write_iter+0x1ba/0x310 mm/filemap.c:4461
 iter_file_splice_write+0x6bc/0xa80 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1161
 splice_direct_to_actor+0x311/0x670 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2db1/0x3000 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811bd77814 of 4 bytes by task 11634 on cpu 0:
 xa_marked include/linux/xarray.h:424 [inline]
 mapping_tagged include/linux/fs.h:507 [inline]
 __writeback_single_inode+0x201/0x7b0 fs/fs-writeback.c:1788
 writeback_single_inode+0x16d/0x3f0 fs/fs-writeback.c:1858
 sync_inode_metadata+0x6e/0xa0 fs/fs-writeback.c:2944
 __generic_file_fsync+0x109/0x160 fs/libfs.c:1569
 fat_file_fsync+0x49/0x100 fs/fat/file.c:191
 vfs_fsync_range+0x10d/0x130 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2616 [inline]
 generic_file_write_iter+0x1ba/0x310 mm/filemap.c:4461
 iter_file_splice_write+0x6bc/0xa80 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1161
 splice_direct_to_actor+0x311/0x670 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2db1/0x3000 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0a000021 -> 0x04000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 11634 Comm: syz.0.3083 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================

Crashes (5030):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/18 16:32 upstream e84d960149e7 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/18 02:48 upstream d12453c7e281 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/17 13:35 upstream d3eeb99bbc99 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/16 00:33 upstream 603c05a1639f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/14 21:48 upstream e0d4140e8043 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/14 08:14 upstream c537e12daeec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/13 19:10 upstream b54345928fa1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/13 05:39 upstream b71e635feefc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/12 15:57 upstream 0f61b1860cc3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/12 15:56 upstream 0f61b1860cc3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/11 12:07 upstream 755bc1335e3b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/10 22:26 upstream 97313d6113ab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/10 09:10 upstream b6151c4e60e5 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/09 20:12 upstream 372800cb95a3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/09 06:12 upstream 623fb9912f6a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/08 17:58 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/06 18:47 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/06 00:00 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/05 06:27 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/04 17:15 upstream 54e82e93ca93 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/03 21:47 upstream aacb0a6d604a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/03 08:47 upstream 805f9a061372 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2026/01/02 19:44 upstream 9b0436804460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/31 21:16 upstream 349bd28a86f2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/31 07:31 upstream c8ebd433459b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/29 22:52 upstream 8640b74557fc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/29 09:26 upstream 7839932417dd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/28 19:56 upstream c875a6c32467 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/27 23:55 upstream d26143bb38e2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/27 10:23 upstream c53f467229a7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/26 20:55 upstream 3f0e9c8cefa9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/24 19:59 upstream ccd1cdca5cd4 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/23 02:36 upstream b927546677c8 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/22 13:31 upstream 9448598b22c5 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/22 00:17 upstream 765b233a9b94 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/21 08:30 upstream 9094662f6707 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/20 19:10 upstream d8ba32c5a460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/19 13:06 upstream dd9b004b7ff3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/18 21:38 upstream 516471569089 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/14 08:02 upstream 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/13 18:51 upstream 9d9c1cfec01c d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/13 04:48 upstream 9551a26f17d9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/11 10:25 upstream d358e5254674 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/10 20:59 upstream 0048fbb4011e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/10 08:16 upstream c9b47175e913 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/09 05:07 upstream cfd4039213e7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/08 15:57 upstream c2f2b01b74be d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/08 02:21 upstream ba65a4e7120a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/07 13:18 upstream 37bb2e7217b0 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/07 00:09 upstream cc3ee4ba57b7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2025/12/06 10:08 upstream 416f99c3b16f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2021/06/26 05:21 upstream b7050b242430 9d2ab5df .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2021/06/22 18:45 upstream 0c18f29aae7c aba2b2fb .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
2021/06/07 18:41 upstream 614124bea77e b718257f .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __xa_clear_mark / xas_find_marked
* Struck through repros no longer work on HEAD.