LinuxLists.cc - [syzbot] [overlayfs?] WARNING in ovl_workdir

2024-05-13 18:28:33

Subject: [syzbot] [overlayfs?] WARNING in ovl_workdir_create (3)

Hello,

syzbot found the following issue on:

HEAD commit: 45db3ab70092 Merge tag '6.9-rc7-ksmbd-fixes' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=169b934c980000
kernel config: https://syzkaller.appspot.com/x/.config?x=2f7a2b43b9e58995
dashboard link: https://syzkaller.appspot.com/bug?extid=8aa3f99a6acb9f8fd429
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0c2a8034002c/disk-45db3ab7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/807e35e2b3a9/vmlinux-45db3ab7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4868b2eab91a/bzImage-45db3ab7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888077f311f0, owner = 0x0, curr 0xffff8880787ebc00, list empty
WARNING: CPU: 1 PID: 8339 at kernel/locking/rwsem.c:1369 __up_write kernel/locking/rwsem.c:1369 [inline]
WARNING: CPU: 1 PID: 8339 at kernel/locking/rwsem.c:1369 up_write+0x469/0x520 kernel/locking/rwsem.c:1632
Modules linked in:
CPU: 1 PID: 8339 Comm: syz-executor.2 Not tainted 6.9.0-rc7-syzkaller-00056-g45db3ab70092 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:__up_write kernel/locking/rwsem.c:1369 [inline]
RIP: 0010:up_write+0x469/0x520 kernel/locking/rwsem.c:1632
Code: ea 03 80 3c 02 00 75 53 48 8b 13 4d 89 f1 41 55 4d 89 f8 4c 89 e1 48 c7 c6 40 b7 2c 8b 48 c7 c7 60 b6 2c 8b e8 08 91 e5 ff 90 <0f> 0b 90 90 5a e9 96 fc ff ff 48 89 ef e8 e5 26 7f 00 e9 03 fd ff
RSP: 0018:ffffc90010ac7928 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff888077f311f0 RCX: ffffc9000baa6000
RDX: 0000000000040000 RSI: ffffffff81517126 RDI: 0000000000000001
RBP: ffff888077f311f8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000002 R12: ffff888077f311f0
R13: ffffffff8b2cb5a0 R14: ffff8880787ebc00 R15: 0000000000000000
FS: 00007f0eebfff6c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020098000 CR3: 0000000021f12000 CR4: 0000000000350ef0
Call Trace:
<TASK>
inode_unlock include/linux/fs.h:800 [inline]
ovl_workdir_create+0x33e/0x820 fs/overlayfs/super.c:359
ovl_make_workdir fs/overlayfs/super.c:656 [inline]
ovl_get_workdir fs/overlayfs/super.c:814 [inline]
ovl_fill_super+0xe6b/0x6720 fs/overlayfs/super.c:1382
vfs_get_super fs/super.c:1268 [inline]
get_tree_nodev+0xdd/0x190 fs/super.c:1287
vfs_get_tree+0x92/0x380 fs/super.c:1779
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__x64_sys_mount+0x297/0x320 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0eec47dd69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0eebfff0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f0eec5ac050 RCX: 00007f0eec47dd69
RDX: 0000000020000080 RSI: 00000000200000c0 RDI: 0000000000000000
RBP: 00007f0eec4ca49e R08: 0000000020000200 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f0eec5ac050 R15: 00007ffe9e328388
</TASK>

---
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

2024-05-17 15:42:24

by Miklos Szeredi

[permalink] [raw]

Subject: Re: [syzbot] [overlayfs?] WARNING in ovl_workdir_create (3)

On Mon, 13 May 2024 at 20:28, syzbot
<[email protected]> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 45db3ab70092 Merge tag '6.9-rc7-ksmbd-fixes' of git://git...
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=169b934c980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2f7a2b43b9e58995
> dashboard link: https://syzkaller.appspot.com/bug?extid=8aa3f99a6acb9f8fd429
> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/0c2a8034002c/disk-45db3ab7.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/807e35e2b3a9/vmlinux-45db3ab7.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/4868b2eab91a/bzImage-45db3ab7.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> ------------[ cut here ]------------
> DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888077f311f0, owner = 0x0, curr 0xffff8880787ebc00, list empty

This is lock corruption on the upper filesystem, definitely not an
overlayfs issue.

#syz unset subsystems

Thanks,
Miklos

2024-05-17 15:43:46

by Aleksandr Nogikh

[permalink] [raw]

Subject: Re: [syzbot] [overlayfs?] WARNING in ovl_workdir_create (3)

On Fri, May 17, 2024 at 5:41 PM 'Miklos Szeredi' via syzkaller-bugs
<[email protected]> wrote:
>
> On Mon, 13 May 2024 at 20:28, syzbot
> <[email protected]> wrote:
> >
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 45db3ab70092 Merge tag '6.9-rc7-ksmbd-fixes' of git://git...
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=169b934c980000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=2f7a2b43b9e58995
> > dashboard link: https://syzkaller.appspot.com/bug?extid=8aa3f99a6acb9f8fd429
> > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> >
> > Unfortunately, I don't have any reproducer for this issue yet.
> >
> > Downloadable assets:
> > disk image: https://storage.googleapis.com/syzbot-assets/0c2a8034002c/disk-45db3ab7.raw.xz
> > vmlinux: https://storage.googleapis.com/syzbot-assets/807e35e2b3a9/vmlinux-45db3ab7.xz
> > kernel image: https://storage.googleapis.com/syzbot-assets/4868b2eab91a/bzImage-45db3ab7.xz
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: [email protected]
> >
> > ------------[ cut here ]------------
> > DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888077f311f0, owner = 0x0, curr 0xffff8880787ebc00, list empty
>
> This is lock corruption on the upper filesystem, definitely not an
> overlayfs issue.
>
> #syz unset subsystems
>
> Thanks,
> Miklos
>
> --

Let's set ext4 then:

#syz set subsystems: ext4