WARNING in ovl_rename

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 19bb613a Linux 4.19.37
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14994b38a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=2f4f1677ff80cdff
dashboard link: https://syzkaller.appspot.com/bug?extid=7d83a9a0f0453ad778a9
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=133e1ceca00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7d83a9...@syzkaller.appspotmail.com

overlayfs: workdir and upperdir must reside under the same mount
overlayfs: workdir and upperdir must reside under the same mount
overlayfs: upper fs does not support tmpfile.
overlayfs: workdir and upperdir must reside under the same mount
overlayfs: upper fs does not support xattr, falling back to index=off and
metacopy=off.
WARNING: CPU: 0 PID: 13354 at fs/overlayfs/dir.c:1177
ovl_rename+0x14ef/0x1870 fs/overlayfs/dir.c:1177
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 13354 Comm: syz-executor.1 Not tainted 4.19.37 #5
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+0x263/0x51d kernel/panic.c:185
overlayfs: workdir and upperdir must reside under the same mount
kobject: 'loop2' (00000000c0c181aa): kobject_uevent_env
__warn.cold+0x20/0x54 kernel/panic.c:540
report_bug+0x263/0x2b0 lib/bug.c:186
kobject: 'loop2' (00000000c0c181aa): fill_kobj_path: path
= '/devices/virtual/block/loop2'
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x204/0x360 arch/x86/kernel/traps.c:296
overlayfs: workdir and upperdir must reside under the same mount
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:997
RIP: 0010:ovl_rename+0x14ef/0x1870 fs/overlayfs/dir.c:1177
Code: e0 04 89 c3 89 c6 e8 a0 39 1f ff 85 db be 01 00 00 00 0f 85 3e f7 ff
ff e8 0e 38 1f ff 4c 89 f7 e9 16 f7 ff ff e8 01 38 1f ff <0f> 0b e9 05 f4
ff ff e8 f5 37 1f ff 48 8b 54 24 68 b8 ff ff 37 00
RSP: 0018:ffff8880799e7ac0 EFLAGS: 00010293
RAX: ffff888081b38000 RBX: 0000000000000000 RCX: ffff88808009a080
RDX: 0000000000000000 RSI: ffffffff824c0f7f RDI: ffff88808009a0d8
RBP: ffff8880799e7bf8 R08: ffff888081b38000 R09: 0000000000000007
R10: ffffed1015d04732 R11: ffff8880ae823993 R12: 0000000000000000
R13: ffff888094572040 R14: ffff888096351e00 R15: ffff8880799e7b90
vfs_rename+0x803/0x1a70 fs/namei.c:4476
do_renameat2+0xb0f/0xc40 fs/namei.c:4626
__do_sys_rename fs/namei.c:4672 [inline]
__se_sys_rename fs/namei.c:4670 [inline]
__x64_sys_rename+0x61/0x80 fs/namei.c:4670
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458da9
Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007efe73ca6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000458da9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 00000000200000c0
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007efe73ca76d4
R13: 00000000004c5d4c R14: 00000000004da328 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
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[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: fa5941f4 Linux 4.14.114
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17897bb0a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d7780000df8e070e
dashboard link: https://syzkaller.appspot.com/bug?extid=bfbc08cdc707dd4d14c7

compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10159390a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:

Reported-by: syzbot+bfbc08...@syzkaller.appspotmail.com

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: 1 PID: 31062 at fs/overlayfs/dir.c:1045
ovl_rename+0xc9d/0xeb0 fs/overlayfs/dir.c:1045

Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 31062 Comm: syz-executor.2 Not tainted 4.14.114 #4

overlayfs: workdir and upperdir must reside under the same mount

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

overlayfs: workdir and upperdir must reside under the same mount

panic+0x1f2/0x438 kernel/panic.c:182
__warn.cold+0x2f/0x34 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:944
RIP: 0010:ovl_rename+0xc9d/0xeb0 fs/overlayfs/dir.c:1045
RSP: 0018:ffff88808570fb68 EFLAGS: 00010297
RAX: ffff888096122180 RBX: ffff888087cd6040 RCX: 1ffff1101195a037
RDX: 0000000000000000 RSI: ffff88808cad0160 RDI: ffff88808cad01b8
RBP: ffff88808570fc50 R08: ffff888096122180 R09: 0000000000000007
R10: 0000000000000000 R11: ffff888096122180 R12: ffff88808ca63000
R13: ffff88807ecc5ca0 R14: 1ffff11010ae1f7d R15: 0000000000000000
vfs_rename+0x556/0x17d0 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+0x1eb/0x630 arch/x86/entry/common.c:289
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x458da9
RSP: 002b:00007fcab3d09c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000052

RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000458da9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 00000000200000c0
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcab3d0a6d4

[syzbot]

syzbot suspects this bug was fixed by commit:

commit f1c5aa5eda08710c2ba619d93126380881fa1114
Author: Amir Goldstein <amir...@gmail.com>
Date: Thu Apr 18 14:42:08 2019 +0000

ovl: detect overlapping layers

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=152343dee00000
start commit: 19bb613a Linux 4.19.37
git tree: linux-4.19.y

kernel config: https://syzkaller.appspot.com/x/.config?x=2f4f1677ff80cdff
dashboard link: https://syzkaller.appspot.com/bug?extid=7d83a9a0f0453ad778a9

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=133e1ceca00000

If the result looks correct, please mark the bug fixed by replying with:

#syz fix: ovl: detect overlapping layers

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[syzbot]

syzbot suspects this bug was fixed by commit:

commit 6890751cfea7d79d998b049647a8c49e2f288ed0
Author: Amir Goldstein <amir...@gmail.com>
Date: Fri Dec 6 06:33:36 2019 +0000

ovl: relax WARN_ON() on rename to self

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1244f959e00000
start commit: 10d6aa56 Linux 4.14.135
git tree: linux-4.14.y
kernel config: https://syzkaller.appspot.com/x/.config?x=ff4089e901d1d013
dashboard link: https://syzkaller.appspot.com/bug?extid=bfbc08cdc707dd4d14c7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d99a62600000

If the result looks correct, please mark the bug fixed by replying with:

#syz fix: ovl: relax WARN_ON() on rename to self