syzbot


KCSAN: data-race in link_path_walk / shrink_dentry_list (4)

Status: auto-closed as invalid on 2022/03/12 22:14
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 437d, last: 300d
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 (5) 1 264d 264d 0/24 auto-closed as invalid on 2022/04/17 20:20
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (6) 1 203d 203d 0/24 auto-closed as invalid on 2022/06/18 02:44
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (2) 3 558d 593d 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 126d 126d 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 472d 476d 0/24 auto-closed as invalid on 2021/09/22 09:34
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list 1 867d 867d 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 0xffff888135267cc0 of 4 bytes by task 817 on cpu 0:
 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:2656 [inline]
 path_mount+0x13f9/0x1c40 fs/namespace.c:3316
 do_mount fs/namespace.c:3337 [inline]
 __do_sys_mount fs/namespace.c:3545 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3522
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3522
 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 0xffff888135267cc0 of 4 bytes by task 815 on cpu 1:
 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]
 do_mount fs/namespace.c:3334 [inline]
 __do_sys_mount fs/namespace.c:3545 [inline]
 __se_sys_mount+0x217/0x2f0 fs/namespace.c:3522
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3522
 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: 1 PID: 815 Comm: syz-executor.0 Not tainted 5.17.0-rc2-syzkaller-00316-g0457e5153e0e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (10):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/05 22:09 upstream 0457e5153e0e a7dab638 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2022/01/15 11:15 upstream 112450df61b7 723cfaf0 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/12/20 06:47 upstream a76c3d035872 44068e19 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/12/11 11:08 upstream 9e65da135b39 49ca1f59 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/12/01 02:59 upstream f080815fdb3e 80270552 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/10/28 19:11 upstream 411a44c24a56 be531bb4 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/10/16 10:06 upstream 8fe31e0995f0 0c5d9412 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/10/04 06:12 upstream 6761a0ae9895 db0f5787 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/10/03 04:54 upstream ab2a7a35c4e7 db0f5787 .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
ci2-upstream-kcsan-gce 2021/09/22 11:15 upstream 92477dd1faa6 169724fe .config log report info KCSAN: data-race in link_path_walk / shrink_dentry_list
* Struck through repros no longer work on HEAD.