syzbot


WARNING in ovl_rename
Status: fixed on 2020/01/18 20:51
Reported-by: syzbot+bfbc08cdc707dd4d14c7@syzkaller.appspotmail.com
Fix commit: 6890751cfea7 ovl: relax WARN_ON() on rename to self
First crash: 1122d, last: 890d

Fix bisection: fixed by (bisect log) :
commit 6890751cfea7d79d998b049647a8c49e2f288ed0
Author: Amir Goldstein <amir73il@gmail.com>
Date: Fri Dec 6 06:33:36 2019 +0000

  ovl: relax WARN_ON() on rename to self

similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in ovl_rename C done done 5 1122d 1119d 16/22 fixed on 2020/02/14 01:19
linux-4.19 WARNING in ovl_rename syz done 1 1122d 1122d 1/1 fixed on 2019/12/16 09:09

Sample crash report:
overlayfs: workdir and upperdir must reside under the same mount
overlayfs: fs on './file1' does not support file handles, falling back to index=off.
overlayfs: upper fs does not support tmpfile.
overlayfs: upper fs does not support xattr.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7260 at fs/overlayfs/dir.c:1045 ovl_rename+0xc9d/0xeb0 fs/overlayfs/dir.c:1045
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7260 Comm: syz-executor.0 Not tainted 4.14.135 #31
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
 panic+0x1f2/0x426 kernel/panic.c:182
 __warn.cold+0x2f/0x36 kernel/panic.c:546
 report_bug+0x216/0x254 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:960
RIP: 0010:ovl_rename+0xc9d/0xeb0 fs/overlayfs/dir.c:1045
RSP: 0018:ffff8880a19efb68 EFLAGS: 00010297
RAX: ffff8880a131a500 RBX: ffff888088a5bb40 RCX: 1ffff1101343e2f7
RDX: 0000000000000000 RSI: ffff88809a1f1760 RDI: ffff88809a1f17b8
RBP: ffff8880a19efc50 R08: ffff8880a131a500 R09: 0000000000000007
R10: 0000000000000000 R11: ffff8880a131a500 R12: ffff8880889a5ce0
R13: ffff8880889281a0 R14: 1ffff1101433df7d R15: 0000000000000000
 vfs_rename+0x551/0x17d0 fs/namei.c:4493
 SYSC_renameat2 fs/namei.c:4641 [inline]
 SyS_renameat2 fs/namei.c:4530 [inline]
 SYSC_rename fs/namei.c:4681 [inline]
 SyS_rename+0x610/0x6d0 fs/namei.c:4679
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459829
RSP: 002b:00007f9f3bc2ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000459829
RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000020000400
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9f3bc2f6d4
R13: 00000000004c6da0 R14: 00000000004dc138 R15: 00000000ffffffff
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-linux-4-14 2019/08/04 07:15 linux-4.14.y 10d6aa565d05 6affd8e8 .config log report syz
ci2-linux-4-14 2019/04/28 09:35 linux-4.14.y fa5941f45d7e b617407b .config log report syz