syzbot


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

Status: moderation: reported on 2019/12/10 21:55
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+6b653cb0a28eee8c400a@syzkaller.appspotmail.com
First crash: 2088d, last: 1d08h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in xas_clear_mark / xas_find_marked mm 6 3 2093d 2099d 0/29 closed as invalid on 2019/10/18 14:11

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

read-write to 0xffff888106b83fd0 of 8 bytes by task 7787 on cpu 0:
 instrument_read_write include/linux/instrumented.h:55 [inline]
 __instrument_read_write_bitop include/asm-generic/bitops/instrumented-non-atomic.h:84 [inline]
 ___test_and_clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:114 [inline]
 node_clear_mark lib/xarray.c:102 [inline]
 xas_clear_mark+0x91/0x180 lib/xarray.c:922
 __folio_start_writeback+0x2ce/0x440 mm/page-writeback.c:3090
 mpage_write_folio fs/mpage.c:615 [inline]
 mpage_writepages+0xd18/0x1250 fs/mpage.c:664
 fat_writepages+0x24/0x30 fs/fat/inode.c:199
 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_file_fsync+0x46/0x140 fs/libfs.c:1526
 fat_file_fsync+0x49/0x100 fs/fat/file.c:191
 vfs_fsync_range+0x10d/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:3031 [inline]
 generic_file_write_iter+0x1b8/0x2f0 mm/filemap.c:4259
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x4a0/0x8e0 fs/read_write.c:686
 ksys_write+0xda/0x1a0 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:746
 x64_sys_call+0x2cdd/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:2
 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 0xffff888106b83fd0 of 8 bytes by task 270 on cpu 1:
 xas_find_chunk include/linux/xarray.h:1752 [inline]
 xas_find_marked+0x218/0x620 lib/xarray.c:1510
 find_get_entry+0x5d/0x380 mm/filemap.c:2038
 filemap_get_folios_tag+0x13b/0x210 mm/filemap.c:2306
 writeback_get_folio mm/page-writeback.c:2463 [inline]
 writeback_iter+0x4bb/0x820 mm/page-writeback.c:2564
 mpage_writepages+0x718/0x1250 fs/mpage.c:663
 fat_writepages+0x24/0x30 fs/fat/inode.c:199
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2636
 __writeback_single_inode+0x80/0x7c0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x480/0xa20 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x94/0x1a0 fs/fs-writeback.c:2047
 wb_writeback+0x266/0x5c0 fs/fs-writeback.c:2158
 wb_check_start_all fs/fs-writeback.c:2284 [inline]
 wb_do_writeback fs/fs-writeback.c:2310 [inline]
 wb_workfn+0x4c9/0x910 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x003ffffff8000000 -> 0x003fffffe0000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 270 Comm: kworker/u8:5 Not tainted 6.16.0-rc5-syzkaller-00038-g733923397fd9 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-7:1)
==================================================================

Crashes (4085):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/09 15:25 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/07/05 04:59 upstream a79a588fc176 d869b261 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/07/04 23:33 upstream 4c06e63b9203 d869b261 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/07/03 01:44 upstream b4911fb0b060 bc80e4f0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/29 11:06 upstream ded779017ad7 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/29 11:06 upstream ded779017ad7 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/26 14:25 upstream ee88bddf7f2f 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/25 03:33 upstream 7595b66ae9de 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/23 05:35 upstream b67ec639010f d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/22 06:20 upstream 739a6c93cc75 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/21 10:33 upstream 11313e2f7812 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/06/20 22:44 upstream 75f5f23f8787 804b3919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/05/25 08:12 upstream d0c22de9995b ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/05/13 06:45 upstream e9565e23cd89 f6671af7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/04/29 07:29 upstream f15d97df5afa aeb6ec69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/04/27 00:51 upstream 5bc1018675ec c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/04/05 20:49 upstream a8662bcd2ff1 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/04/05 09:57 upstream a52a3c18cdf3 c53ea9c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/03/22 11:03 upstream 88d324e69ea9 c6512ef7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/03/17 10:37 upstream 4701f33a1070 948c34e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/03/10 15:12 upstream 80e54e84911a 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/03/06 05:34 upstream bb2281fb05e5 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/02/05 18:58 upstream 5c8c229261f1 4dc70884 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/02/01 00:56 upstream 69b8923f5003 aa47157c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/26 22:02 upstream c2da8b3f914f 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/26 10:35 upstream aa22f4da2a46 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/25 23:12 upstream 0f8e26b38d7a 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/23 18:15 upstream d0d106a2bd21 521b0ce3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/23 10:14 upstream 21266b8df522 a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/22 20:22 upstream df60eac9efe8 a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/22 08:07 upstream c4b9570cfb63 da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/21 18:41 upstream b9d8a295ed6b da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/21 16:45 upstream 95ec54a420b8 da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/21 09:15 upstream 95ec54a420b8 6e87cfa2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/16 18:25 upstream ce69b4019001 f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/16 14:30 upstream 619f0b6fad52 f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/15 18:23 upstream 619f0b6fad52 968edaf4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/14 17:00 upstream c45323b7560e f310a27d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/12 21:34 upstream be548645527a 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/11 21:16 upstream b62cef9a5c67 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/10 18:43 upstream 2144da25584e 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/10 16:05 upstream 2144da25584e 67d7ec0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/10 02:11 upstream 643e2e259c2b 67d7ec0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/09 09:03 upstream eea6e4b4dfb8 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/05 21:09 upstream 9244696b34f2 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2025/01/04 19:47 upstream ab75170520d4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in xas_clear_mark / xas_find_marked
2021/01/17 10:22 upstream 0da0a8a0a0e1 813be542 .config console log report info ci2-upstream-kcsan-gce
2019/10/22 14:09 https://github.com/google/ktsan.git kcsan 05f2236801fe 4ee855e7 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.