syzbot


KCSAN: data-race in xas_find_marked / xas_set_mark

Status: moderation: reported on 2019/12/05 04:45
Subsystems: mm fs
[Documentation on labels]
Reported-by: syzbot+238e9bb046564c2c4d4a@syzkaller.appspotmail.com
First crash: 2093d, last: 15h43m

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

write to 0xffff888106e3f6ac of 4 bytes by task 8635 on cpu 0:
 xa_mark_set lib/xarray.c:71 [inline]
 xas_set_mark+0x12b/0x140 lib/xarray.c:900
 __folio_start_writeback+0x1dd/0x440 mm/page-writeback.c:3073
 ext4_bio_write_folio+0x5ad/0x9f0 fs/ext4/page-io.c:583
 mpage_submit_folio+0xe4/0x170 fs/ext4/inode.c:2057
 mpage_process_page_bufs+0x39b/0x4a0 fs/ext4/inode.c:2170
 mpage_prepare_extent_to_map+0x741/0xaa0 fs/ext4/inode.c:2675
 ext4_do_writepages+0x6ea/0x21c0 fs/ext4/inode.c:2816
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:2953
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2636
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 filemap_write_and_wait_range+0x144/0x340 mm/filemap.c:691
 filemap_invalidate_pages+0xa4/0x1a0 mm/filemap.c:2815
 kiocb_invalidate_pages+0x6e/0x80 mm/filemap.c:2834
 __iomap_dio_rw+0x5d4/0x1250 fs/iomap/direct-io.c:703
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:823
 ext4_dio_write_iter fs/ext4/file.c:580 [inline]
 ext4_file_write_iter+0xad9/0xf00 fs/ext4/file.c:721
 iter_file_splice_write+0x5f2/0x970 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1158
 splice_direct_to_actor+0x312/0x680 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1227
 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+0xb39/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888106e3f6ac of 4 bytes by task 8647 on cpu 1:
 xa_marked include/linux/xarray.h:424 [inline]
 xas_find_marked+0x5dc/0x620 lib/xarray.c:1483
 find_get_entry+0x5d/0x380 mm/filemap.c:2038
 filemap_get_folios_tag+0x92/0x210 mm/filemap.c:2306
 mpage_prepare_extent_to_map+0x320/0xaa0 fs/ext4/inode.c:2577
 ext4_do_writepages+0x6ea/0x21c0 fs/ext4/inode.c:2816
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:2953
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2636
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 file_write_and_wait_range+0x156/0x2c0 mm/filemap.c:794
 generic_buffers_fsync_noflush+0x45/0x120 fs/buffer.c:609
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x1ab/0x690 fs/ext4/fsync.c:147
 vfs_fsync_range+0x10d/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:3031 [inline]
 ext4_buffered_write_iter+0x34f/0x3c0 fs/ext4/file.c:305
 ext4_dio_write_iter fs/ext4/file.c:613 [inline]
 ext4_file_write_iter+0xdbf/0xf00 fs/ext4/file.c:721
 iter_file_splice_write+0x5f2/0x970 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1158
 splice_direct_to_actor+0x312/0x680 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1227
 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+0xb39/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 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: 1 UID: 0 PID: 8647 Comm: syz.3.1902 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================

Crashes (2061):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/15 13:02 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/15 01:55 upstream 347e9f5043c8 d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/13 21:47 upstream 5d5d62298b8b 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/12 13:00 upstream 379f604cc3dc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/12 00:07 upstream 40f92e79b0aa 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/10 21:56 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/10 10:59 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/09 02:55 upstream d006330be3f7 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/07 03:46 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/06 15:02 upstream 1f988d0788f5 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/04 08:16 upstream 17bbde2e1716 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/03 06:22 upstream b4911fb0b060 115ceea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/07/02 02:03 upstream 66701750d556 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/29 12:47 upstream dfba48a70cb6 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/27 03:29 upstream f02769e7f272 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/26 23:12 upstream ee88bddf7f2f 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/26 11:21 upstream ee88bddf7f2f 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/25 19:41 upstream 92ca6c498a5e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/25 04:50 upstream 7595b66ae9de 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/24 20:17 upstream 78f4e737a53e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/24 11:45 upstream 78f4e737a53e e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/22 06:45 upstream 739a6c93cc75 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/19 08:47 upstream fb4d33ab452e ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/18 14:38 upstream 52da431bf03b ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/18 09:39 upstream 52da431bf03b e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/17 20:34 upstream 4663747812d1 e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/16 16:31 upstream e04c78d86a96 d1716036 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/15 21:28 upstream 08215f5486ec 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/15 06:41 upstream 8c6bc74c7f89 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/14 16:55 upstream 4774cfe3543a 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/14 14:36 upstream 4774cfe3543a 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/14 01:24 upstream 02adc1490e6d 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/13 19:27 upstream 02adc1490e6d 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/12 23:22 upstream 27605c8c0f69 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/12 09:55 upstream 2c4a1f3fe03e 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/12 09:51 upstream 2c4a1f3fe03e 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/11 20:15 upstream 488ef3560196 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/11 17:17 upstream aef17cb3d3c4 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/10 22:31 upstream aef17cb3d3c4 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/10 17:07 upstream f09079bd04a9 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/10 08:07 upstream f09079bd04a9 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/06/09 09:19 upstream 19272b37aa4f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2021/01/16 09:14 upstream 1d94330a437a 65a7a854 .config console log report info ci2-upstream-kcsan-gce
2019/10/23 02:27 https://github.com/google/ktsan.git kcsan 05f2236801fe d0686497 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.