syzbot


KCSAN: data-race in xas_find_marked / xas_set_mark

Status: moderation: reported on 2019/12/05 04:45
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+238e9bb046564c2c4d4a@syzkaller.appspotmail.com
First crash: 2159d, last: 5h05m

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

write to 0xffff88810736e54c of 4 bytes by task 8099 on cpu 1:
 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:3071
 ext4_bio_write_folio+0x5ad/0x9f0 fs/ext4/page-io.c:583
 mpage_submit_folio fs/ext4/inode.c:2080 [inline]
 mpage_process_page_bufs+0x4a1/0x620 fs/ext4/inode.c:2191
 mpage_prepare_extent_to_map+0x786/0xc00 fs/ext4/inode.c:2736
 ext4_do_writepages+0xa05/0x2750 fs/ext4/inode.c:2929
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:3025
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2634
 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+0x10a/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:3043 [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+0x666/0xa60 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+0x312/0x680 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0xda/0x150 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+0x2bb0/0x2ff0 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 0xffff88810736e54c of 4 bytes by task 8100 on cpu 0:
 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:2039
 filemap_get_folios_tag+0x92/0x210 mm/filemap.c:2307
 mpage_prepare_extent_to_map+0x320/0xc00 fs/ext4/inode.c:2637
 ext4_do_writepages+0x708/0x2750 fs/ext4/inode.c:2877
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:3025
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2634
 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+0x10a/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:3043 [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+0x666/0xa60 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+0x312/0x680 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0xda/0x150 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+0x2bb0/0x2ff0 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: 0 UID: 0 PID: 8100 Comm: syz.7.1755 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================

Crashes (2213):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/20 01:22 upstream cd89d487374c 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/19 19:44 upstream 097a6c336d00 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/18 22:37 upstream cbf658dd0941 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/18 09:20 upstream 8b789f2b7602 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/17 22:57 upstream d4b779985a6c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/17 08:25 upstream 5aca7966d2a7 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/16 00:51 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/15 11:10 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/15 11:10 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/14 21:59 upstream 79e8447ec662 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/14 08:28 upstream f83a4f2a4d8c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/13 19:30 upstream 5cd64d4f9268 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/12 17:30 upstream 320475fbd590 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/11 20:03 upstream 02ffd6f89c50 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/11 16:19 upstream 02ffd6f89c50 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/10 21:07 upstream 7aac71907bde fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/10 00:53 upstream 9dd1835ecda5 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/09 20:22 upstream 9dd1835ecda5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/08 20:43 upstream f777d1112ee5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/08 09:33 upstream 76eeb9b8de98 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/07 19:42 upstream 6ab41fca2e80 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/07 05:37 upstream b236920731dd d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/06 09:24 upstream d1d10cea0895 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/06 04:22 upstream c8ed9b5c02a5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/04 17:38 upstream 08b06c30a445 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/04 03:59 upstream b9a10f876409 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/03 20:30 upstream ec299e4dc21e 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/02 22:14 upstream e6b9dce0aeeb 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/02 14:02 upstream b320789d6883 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/09/01 07:40 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/31 19:56 upstream 5c3b3264e585 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/31 03:34 upstream c8bc81a52d5a 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/30 12:26 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/29 23:00 upstream fb679c832b64 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/29 19:51 upstream fb679c832b64 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/29 11:23 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/27 19:44 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/26 17:13 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/26 06:05 upstream fab1beda7597 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/26 02:21 upstream b6add54ba618 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/24 16:46 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/23 21:14 upstream 8d245acc1e88 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_find_marked / xas_set_mark
2025/08/23 08:21 upstream 6debb6904172 bf27483f .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.