syzbot


WARNING in ovl_rename

Status: fixed on 2020/02/14 01:19
Subsystems: overlayfs
[Documentation on labels]
Reported-by: syzbot+bb1836a212e69f8e201a@syzkaller.appspotmail.com
Fix commit: 6889ee5a53b8 ovl: relax WARN_ON() on rename to self
First crash: 1796d, last: 1796d
Cause bisection: introduced by (bisect log) :
commit 6eaf011144af10cad34c0d46f82e50d382c8e926
Author: Amir Goldstein <amir73il@gmail.com>
Date: Thu Oct 12 16:03:04 2017 +0000

  ovl: fix EIO from lookup of non-indexed upper

Crash: WARNING in ovl_rename (log)
Repro: syz .config
  
Fix bisection: fixed by (bisect log) :
commit 146d62e5a5867fbf84490d82455718bfb10fe824
Author: Amir Goldstein <amir73il@gmail.com>
Date: Thu Apr 18 14:42:08 2019 +0000

  ovl: detect overlapping layers

  
Discussions (5)
Title Replies (including bot) Last reply
[PATCH 5.4 000/177] 5.4.4-stable review 188 (188) 2019/12/17 18:48
[PATCH 5.3 000/180] 5.3.17-stable review 185 (185) 2019/12/17 18:19
[PATCH 4.19 000/140] 4.19.90-stable review 150 (150) 2019/12/17 18:18
[PATCH 4.14 000/267] 4.14.159-stable review 280 (280) 2019/12/17 18:18
WARNING in ovl_rename 1 (3) 2019/12/06 06:46
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 WARNING in ovl_rename syz done 1 1796d 1796d 1/1 fixed on 2019/12/16 09:09
linux-4.14 WARNING in ovl_rename syz done 2 1564d 1796d 1/1 fixed on 2020/01/18 20:51

Sample crash report:
WARNING: CPU: 1 PID: 17205 at fs/overlayfs/dir.c:1176 ovl_rename+0x159c/0x1940 fs/overlayfs/dir.c:1176
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 17205 Comm: syz-executor092 Not tainted 5.1.0-rc6+ #88
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+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2cb/0x65c kernel/panic.c:214
 __warn.cold+0x20/0x45 kernel/panic.c:571
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:ovl_rename+0x159c/0x1940 fs/overlayfs/dir.c:1176
Code: 80 00 00 00 e8 45 f7 19 ff 8b b4 24 80 00 00 00 85 f6 0f 85 cd f6 ff ff e8 b1 f5 19 ff 4c 89 f7 e9 a5 f6 ff ff e8 a4 f5 19 ff <0f> 0b e9 a4 f3 ff ff e8 98 f5 19 ff 48 8b 54 24 70 b8 ff ff 37 00
RSP: 0018:ffff88808a8c7ad8 EFLAGS: 00010293
RAX: ffff88807888e5c0 RBX: 0000000000000000 RCX: ffff888088a43600
RDX: 0000000000000000 RSI: ffffffff8256970c RDI: ffff888088a43658
RBP: ffff88808a8c7bf8 R08: ffff88807888e5c0 R09: 0000000000000008
R10: ffffed1015d25bc7 R11: ffff8880ae92de3b R12: ffff88807ebef5c0
R13: 0000000000000000 R14: ffff8880836ae340 R15: ffff88808a8c7b90
 vfs_rename+0x803/0x1ac0 fs/namei.c:4475
 do_renameat2+0xb0f/0xc40 fs/namei.c:4625
 __do_sys_rename fs/namei.c:4671 [inline]
 __se_sys_rename fs/namei.c:4669 [inline]
 __x64_sys_rename+0x61/0x80 fs/namei.c:4669
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x449839
Code: e8 7c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 1b 05 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd99ee75ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00000000006e5a08 RCX: 0000000000449839
RDX: 0000000000449839 RSI: 0000000020000140 RDI: 00000000200000c0
RBP: 00000000006e5a00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e5a0c
R13: 00007fff986b9cef R14: 00007fd99ee769c0 R15: 20c49ba5e353f7cf
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/28 06:25 upstream 037904a22bf8 b617407b .config console log report syz C ci-upstream-kasan-gce-selinux-root
2019/04/28 06:15 upstream 037904a22bf8 b617407b .config console log report syz C ci-upstream-kasan-gce-root
2019/04/28 05:17 upstream 037904a22bf8 b617407b .config console log report syz ci-upstream-kasan-gce-smack-root
2019/04/28 06:10 linux-next 3ddfa8af5dc9 b617407b .config console log report syz ci-upstream-linux-next-kasan-gce-root
2019/04/28 04:30 upstream 037904a22bf8 b617407b .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.