syzbot


KCSAN: data-race in write_cache_pages / write_cache_pages (4)

Status: auto-closed as invalid on 2021/09/04 02:13
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 558d, last: 558d
similar bugs (8):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in write_cache_pages / write_cache_pages (5) 4 424d 467d 0/24 auto-closed as invalid on 2022/01/15 16:41
upstream KCSAN: data-race in write_cache_pages / write_cache_pages (3) 1 610d 610d 0/24 auto-closed as invalid on 2021/07/13 22:52
upstream KCSAN: data-race in write_cache_pages / write_cache_pages (7) 1 257d 257d 0/24 auto-closed as invalid on 2022/07/02 07:32
upstream KCSAN: data-race in write_cache_pages / write_cache_pages 2 1121d 1144d 0/24 auto-closed as invalid on 2020/03/24 21:40
upstream KCSAN: data-race in write_cache_pages / write_cache_pages (9) 1 138d 138d 0/24 auto-obsoleted due to no activity on 2022/10/29 12:30
upstream KCSAN: data-race in write_cache_pages / write_cache_pages (8) 2 199d 220d 0/24 auto-closed as invalid on 2022/08/29 06:43
upstream KCSAN: data-race in write_cache_pages / write_cache_pages (2) 2 823d 794d 0/24 auto-closed as invalid on 2020/12/21 11:55
upstream KCSAN: data-race in write_cache_pages / write_cache_pages (6) 2 313d 339d 0/24 auto-closed as invalid on 2022/05/06 22:51

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

write to 0xffff888101ba6610 of 8 bytes by task 1783 on cpu 1:
 write_cache_pages+0x7c4/0x810 mm/page-writeback.c:2300
 generic_writepages+0x64/0xa0 mm/page-writeback.c:2340
 blkdev_writepages+0x19/0x20 fs/block_dev.c:1679
 do_writepages+0x7b/0x150 mm/page-writeback.c:2355
 __filemap_fdatawrite_range mm/filemap.c:413 [inline]
 __filemap_fdatawrite mm/filemap.c:421 [inline]
 filemap_flush+0x132/0x160 mm/filemap.c:448
 __sync_blockdev+0x69/0x70 fs/block_dev.c:525
 __sync_filesystem fs/sync.c:40 [inline]
 sync_filesystem+0xcb/0x160 fs/sync.c:64
 generic_shutdown_super+0x42/0x230 fs/super.c:448
 kill_block_super+0x4a/0x90 fs/super.c:1395
 deactivate_locked_super+0x65/0xd0 fs/super.c:335
 deactivate_super+0x85/0x90 fs/super.c:366
 cleanup_mnt+0x267/0x2d0 fs/namespace.c:1136
 __cleanup_mnt+0x15/0x20 fs/namespace.c:1143
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x49/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888101ba6610 of 8 bytes by task 97 on cpu 0:
 write_cache_pages+0xe5/0x810 mm/page-writeback.c:2188
 generic_writepages+0x64/0xa0 mm/page-writeback.c:2340
 blkdev_writepages+0x19/0x20 fs/block_dev.c:1679
 do_writepages+0x7b/0x150 mm/page-writeback.c:2355
 __writeback_single_inode+0x80/0x440 fs/fs-writeback.c:1613
 writeback_sb_inodes+0x563/0xd10 fs/fs-writeback.c:1878
 __writeback_inodes_wb fs/fs-writeback.c:1947 [inline]
 wb_writeback+0x327/0x700 fs/fs-writeback.c:2053
 wb_check_background_flush fs/fs-writeback.c:2121 [inline]
 wb_do_writeback+0x4ce/0x510 fs/fs-writeback.c:2209
 wb_workfn+0xc8/0x520 fs/fs-writeback.c:2237
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

value changed: 0x0000000000000000 -> 0x0000000000000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 97 Comm: kworker/u4:2 Tainted: G        W         5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-7:3)
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-kcsan-gce 2021/07/31 02:08 upstream 4669e13cd67f 6c236867 .config console log report info KCSAN: data-race in write_cache_pages / write_cache_pages
* Struck through repros no longer work on HEAD.