syzbot


KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch (2)

Status: auto-closed as invalid on 2022/08/23 18:22
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 192d, last: 141d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch 1 233d 233d 0/24 auto-closed as invalid on 2022/05/23 16:48
upstream KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch (3) 2 76d 86d 0/24 auto-obsoleted due to no activity on 2022/10/27 09:21

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

read-write to 0xffff8881027bcc48 of 8 bytes by task 21754 on cpu 1:
 page_cache_delete_batch+0x445/0x470 mm/filemap.c:315
 delete_from_page_cache_batch+0x18f/0x2a0 mm/filemap.c:334
 truncate_inode_pages_range+0x3ca/0xae0 mm/truncate.c:370
 truncate_inode_pages+0x20/0x30 mm/truncate.c:452
 kill_bdev block/bdev.c:77 [inline]
 blkdev_flush_mapping+0xde/0x230 block/bdev.c:663
 blkdev_put_whole block/bdev.c:694 [inline]
 blkdev_put+0x32a/0x420 block/bdev.c:954
 blkdev_close+0x32/0x40 block/fops.c:495
 __fput+0x292/0x510 fs/file_table.c:317
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:177
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x124/0x130 kernel/entry/common.c:169
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881027bcc48 of 8 bytes by task 1923 on cpu 0:
 nr_blockdev_pages+0x7f/0xd0 block/bdev.c:524
 si_meminfo+0x3a/0x60 mm/page_alloc.c:5835
 update_defense_level+0x46/0x560 net/netfilter/ipvs/ip_vs_ctl.c:102
 defense_work_handler+0x1b/0x80 net/netfilter/ipvs/ip_vs_ctl.c:236
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

value changed: 0x00000000000000ba -> 0x000000000000009c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1923 Comm: kworker/0:4 Not tainted 5.19.0-rc7-syzkaller-00005-gca85855bdcae-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Workqueue: events_long defense_work_handler

==================================================================

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/07/19 18:20 upstream ca85855bdcae 72a3cc0c .config log report info KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch
ci2-upstream-kcsan-gce 2022/07/01 01:08 upstream 1a0e93df1e10 1434eec0 .config log report info KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch
ci2-upstream-kcsan-gce 2022/06/20 04:20 upstream 05c6ca8512f2 8f633d84 .config log report info KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch
ci2-upstream-kcsan-gce 2022/05/29 07:59 upstream 664a393a2663 a46af346 .config log report info KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch
* Struck through repros no longer work on HEAD.