syzbot


KCSAN: data-race in fsnotify_perm / shrink_dentry_list

Status: auto-closed as invalid on 2021/11/15 10:17
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 420d, last: 420d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in fsnotify_perm / shrink_dentry_list (2) 2 354d 361d 0/24 auto-closed as invalid on 2022/01/20 15:48

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

write to 0xffff88810132b0c0 of 4 bytes by task 17224 on cpu 0:
 shrink_dentry_list+0x127/0x340 fs/dcache.c:423
 shrink_dcache_sb+0x188/0x2d0 fs/dcache.c:1296
 reconfigure_super+0x2aa/0x4f0 fs/super.c:889
 do_remount fs/namespace.c:2650 [inline]
 path_mount+0x145a/0x1d20 fs/namespace.c:3310
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3516
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3516
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88810132b0c0 of 4 bytes by task 1112 on cpu 1:
 fsnotify_parent include/linux/fsnotify.h:69 [inline]
 fsnotify_file include/linux/fsnotify.h:99 [inline]
 fsnotify_perm+0x2ce/0x370 include/linux/fsnotify.h:124
 security_file_open+0x85/0x90 security/security.c:1638
 do_dentry_open+0x232/0x860 fs/open.c:809
 vfs_open+0x43/0x50 fs/open.c:945
 do_open fs/namei.c:3428 [inline]
 path_openat+0x17c3/0x1ec0 fs/namei.c:3561
 do_filp_open+0x105/0x220 fs/namei.c:3588
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_openat fs/open.c:1232 [inline]
 __se_sys_openat fs/open.c:1227 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1227
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 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: 1112 Comm: syz-executor.5 Not tainted 5.15.0-rc5-syzkaller #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 2021/10/11 10:10 upstream 64570fbc14f8 838e7e2c .config log report info KCSAN: data-race in fsnotify_perm / shrink_dentry_list
* Struck through repros no longer work on HEAD.