syzbot


KCSAN: data-race in link_path_walk / shrink_dentry_list (5)

Status: auto-closed as invalid on 2022/04/17 20:20
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 267d, last: 267d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (6) 1 206d 206d 0/24 auto-closed as invalid on 2022/06/18 02:44
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (4) 10 303d 440d 0/24 auto-closed as invalid on 2022/03/12 22:14
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (2) 3 561d 596d 0/24 auto-closed as invalid on 2021/06/27 19:17
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (7) 1 129d 129d 0/24 auto-closed as invalid on 2022/09/03 00:29
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (3) 2 475d 479d 0/24 auto-closed as invalid on 2021/09/22 09:34
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list 1 870d 870d 0/24 auto-closed as invalid on 2020/08/23 06:27

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

write to 0xffff888120e850c0 of 4 bytes by task 9497 on cpu 1:
 shrink_dentry_list+0x127/0x540 fs/dcache.c:448
 shrink_dcache_sb+0x188/0x2d0 fs/dcache.c:1321
 reconfigure_super+0x146/0x540 fs/super.c:888
 do_remount fs/namespace.c:2686 [inline]
 path_mount+0x13f9/0x1c40 fs/namespace.c:3346
 do_mount fs/namespace.c:3367 [inline]
 __do_sys_mount fs/namespace.c:3575 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3552
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3552
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888120e850c0 of 4 bytes by task 1825 on cpu 0:
 link_path_walk+0x409/0x990 fs/namei.c:2309
 path_lookupat+0x8b/0x3d0 fs/namei.c:2498
 filename_lookup+0x130/0x310 fs/namei.c:2528
 user_path_at_empty+0x3e/0x110 fs/namei.c:2851
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0xa3/0x3c0 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 vfs_lstat include/linux/fs.h:3287 [inline]
 __do_sys_newlstat fs/stat.c:398 [inline]
 __se_sys_newlstat+0x5d/0x250 fs/stat.c:392
 __x64_sys_newlstat+0x2d/0x40 fs/stat.c:392
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00280440 -> 0x00200040

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1825 Comm: syz-executor.1 Not tainted 5.17.0-rc7-syzkaller-00241-gf0e18b03fcaf-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/03/13 20:12 upstream f0e18b03fcaf 9e8eaa75 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
* Struck through repros no longer work on HEAD.