syzbot


KCSAN: data-race in __d_lookup_done / __dentry_kill (6)

Status: auto-closed as invalid on 2022/05/29 05:25
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 156d, last: 156d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (5) 5 481d 517d 0/24 auto-closed as invalid on 2021/07/08 04:16
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (3) 1 723d 723d 0/24 auto-closed as invalid on 2020/11/08 00:33
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (4) 3 602d 626d 0/24 auto-closed as invalid on 2021/03/09 07:41
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill (2) 4 805d 825d 0/24 auto-closed as invalid on 2020/08/18 04:12
upstream KCSAN: data-race in __d_lookup_done / __dentry_kill 29 891d 1065d 0/24 auto-closed as invalid on 2020/06/18 14:14

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __d_lookup_done / __dentry_kill

read-write to 0xffff888121414780 of 4 bytes by task 10534 on cpu 1:
 __d_lookup_done+0x86/0x240 fs/dcache.c:2709
 __d_add+0x33c/0x470 fs/dcache.c:2729
 d_splice_alias+0xd5/0x310 fs/dcache.c:3126
 proc_lookup_de+0x1e3/0x230 fs/proc/generic.c:258
 proc_tgid_net_lookup+0x3f/0xc0 fs/proc/proc_net.c:299
 lookup_open fs/namei.c:3308 [inline]
 open_last_lookups fs/namei.c:3400 [inline]
 path_openat+0xb0f/0x1b30 fs/namei.c:3606
 do_filp_open+0x105/0x220 fs/namei.c:3636
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1213
 do_sys_open fs/open.c:1229 [inline]
 __do_sys_openat fs/open.c:1245 [inline]
 __se_sys_openat fs/open.c:1240 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1240
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888121414780 of 4 bytes by task 10533 on cpu 0:
 dentry_unlist fs/dcache.c:572 [inline]
 __dentry_kill+0x1e7/0x450 fs/dcache.c:603
 dentry_kill+0x8d/0x1e0
 dput+0x11e/0x1f0 fs/dcache.c:913
 path_put fs/namei.c:557 [inline]
 terminate_walk+0xfa/0x250 fs/namei.c:672
 path_openat+0x1799/0x1b30 fs/namei.c:3610
 do_filp_open+0x105/0x220 fs/namei.c:3636
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1213
 do_sys_open fs/open.c:1229 [inline]
 __do_sys_openat fs/open.c:1245 [inline]
 __se_sys_openat fs/open.c:1240 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1240
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x1000000c -> 0x0040000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10533 Comm: syz-executor.5 Not tainted 5.18.0-rc3-syzkaller-00218-g13bc32bad705-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 2022/04/24 05:22 upstream 13bc32bad705 131df97d .config log report info KCSAN: data-race in __d_lookup_done / __dentry_kill
* Struck through repros no longer work on HEAD.