syzbot


KCSAN: data-race in dput / vfs_rmdir (2)

Status: auto-closed as invalid on 2020/12/21 11:51
Reported-by: syzbot+e8c40c3114482d1255c2@syzkaller.appspotmail.com
First crash: 661d, last: 633d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in dput / vfs_rmdir 1 711d 711d 0/23 auto-closed as invalid on 2020/09/30 12:38
upstream KCSAN: data-race in dput / vfs_rmdir (3) 3 535d 572d 0/23 auto-closed as invalid on 2021/03/25 09:59

Sample crash report:
==================================================================
BUG: KCSAN: data-race in dput / vfs_rmdir

read-write to 0xffff88810d975300 of 4 bytes by task 15149 on cpu 0:
 dont_mount include/linux/dcache.h:354 [inline]
 vfs_rmdir+0x193/0x290 fs/namei.c:3719
 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

read to 0xffff88810d975300 of 4 bytes by task 15147 on cpu 1:
 fast_dput fs/dcache.c:746 [inline]
 dput+0x2f/0x420 fs/dcache.c:865
 path_put fs/namei.c:496 [inline]
 do_unlinkat+0x37a/0x4d0 fs/namei.c:3912
 __do_sys_unlink fs/namei.c:3943 [inline]
 __se_sys_unlink fs/namei.c:3941 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:3941
 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: 15147 Comm: syz-executor.5 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 15147 Comm: syz-executor.5 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x116/0x15d lib/dump_stack.c:118
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x46a/0x4d0 kernel/kcsan/core.c:568
 fast_dput fs/dcache.c:746 [inline]
 dput+0x2f/0x420 fs/dcache.c:865
 path_put fs/namei.c:496 [inline]
 do_unlinkat+0x37a/0x4d0 fs/namei.c:3912
 __do_sys_unlink fs/namei.c:3943 [inline]
 __se_sys_unlink fs/namei.c:3941 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:3941
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45deb9
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1729513c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000038180 RCX: 000000000045deb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 000000000118bff8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfd4
R13: 00007fff00ec12ff R14: 00007f17295149c0 R15: 000000000118bfd4
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/11/11 18:20 upstream eccc87672492 cca87986 .config log report info
ci2-upstream-kcsan-gce 2020/10/15 10:50 upstream 3e4fb4346c78 63869021 .config log report info