syzbot


KCSAN: data-race in dentry_lru_isolate / link_path_walk (2)

Status: auto-closed as invalid on 2020/12/24 05:06
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+631772bbcfed57c66e89@syzkaller.appspotmail.com
First crash: 1263d, last: 1247d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in dentry_lru_isolate / link_path_walk (4) fs 1 1086d 1086d 0/26 auto-closed as invalid on 2021/06/03 17:49
upstream KCSAN: data-race in dentry_lru_isolate / link_path_walk (5) fs 1 376d 376d 0/26 auto-obsoleted due to no activity on 2023/05/14 03:33
upstream KCSAN: data-race in dentry_lru_isolate / link_path_walk fs 1 1305d 1305d 0/26 auto-closed as invalid on 2020/10/27 03:28
upstream KCSAN: data-race in dentry_lru_isolate / link_path_walk (3) fs 2 1173d 1193d 0/26 auto-closed as invalid on 2021/03/08 07:19

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

write to 0xffff88800d713600 of 4 bytes by task 2185 on cpu 1:
 d_lru_isolate fs/dcache.c:442 [inline]
 dentry_lru_isolate+0x9f/0x200 fs/dcache.c:1166
 __list_lru_walk_one+0xfb/0x300 mm/list_lru.c:222
 list_lru_walk_one+0x75/0x90 mm/list_lru.c:266
 list_lru_shrink_walk include/linux/list_lru.h:195 [inline]
 prune_dcache_sb+0x67/0xa0 fs/dcache.c:1220
 super_cache_scan+0x23e/0x2e0 fs/super.c:105
 do_shrink_slab+0x28b/0x550 mm/vmscan.c:513
 shrink_slab+0xea/0x1c0 mm/vmscan.c:674
 shrink_node_memcgs+0x27a/0x410 mm/vmscan.c:2656
 shrink_node+0x9d2/0x11d0 mm/vmscan.c:2771
 kswapd_shrink_node mm/vmscan.c:3514 [inline]
 balance_pgdat+0x6a5/0xc40 mm/vmscan.c:3672
 kswapd+0x1de/0x310 mm/vmscan.c:3929
 kthread+0x1fa/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff88800d713600 of 4 bytes by task 4890 on cpu 0:
 link_path_walk+0x329/0x710 fs/namei.c:2146
 path_openat+0x19f/0x20a0 fs/namei.c:3365
 do_filp_open+0xbd/0x1d0 fs/namei.c:3396
 do_sys_openat2+0xa3/0x240 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_open fs/open.c:1192 [inline]
 __se_sys_open fs/open.c:1188 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1188
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4890 Comm: systemd-udevd Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/19 05:05 upstream c2e7554e1b85 0767f13f .config console log report info ci2-upstream-kcsan-gce
2020/11/03 21:17 upstream b7cbaf59f62f cba33199 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.