syzbot


KCSAN: data-race in dentry_lru_isolate_shrink / may_delete

Status: auto-closed as invalid on 2020/12/21 11:58
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+82292fb8e493fd8979c3@syzkaller.appspotmail.com
First crash: 1236d, last: 1236d

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

write to 0xffff88801258ed80 of 4 bytes by task 8191 on cpu 0:
 d_lru_shrink_move fs/dcache.c:453 [inline]
 dentry_lru_isolate_shrink+0x7b/0x100 fs/dcache.c:1240
 __list_lru_walk_one+0xfb/0x300 mm/list_lru.c:222
 list_lru_walk_one mm/list_lru.c:266 [inline]
 list_lru_walk_node+0x63/0x1a0 mm/list_lru.c:295
 list_lru_walk include/linux/list_lru.h:215 [inline]
 shrink_dcache_sb+0x97/0x1c0 fs/dcache.c:1259
 reconfigure_super+0x267/0x4d0 fs/super.c:940
 do_remount fs/namespace.c:2612 [inline]
 path_mount+0x13b1/0x1c10 fs/namespace.c:3197
 do_mount fs/namespace.c:3218 [inline]
 __do_sys_mount fs/namespace.c:3426 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3403
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3403
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88801258ed80 of 4 bytes by task 8474 on cpu 1:
 may_delete+0x2f7/0x420 fs/namei.c:2707
 vfs_rmdir+0x25/0x290 fs/namei.c:3694
 do_rmdir+0x16e/0x300 fs/namei.c:3774
 __do_sys_rmdir fs/namei.c:3792 [inline]
 __se_sys_rmdir fs/namei.c:3790 [inline]
 __x64_sys_rmdir+0x2c/0x30 fs/namei.c:3790
 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: 1 PID: 8474 Comm: syz-executor.1 Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/07 22:59 upstream 659caaf65dc9 cba33199 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.