2023-07-11 04:37:24

by syzbot

[permalink] [raw]
Subject: [syzbot] [overlayfs?] general protection fault in ovl_init_uuid_xattr

Hello,

syzbot found the following issue on:

HEAD commit: 123212f53f3e Add linux-next specific files for 20230707
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12353b44a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=15ec80b62f588543
dashboard link: https://syzkaller.appspot.com/bug?extid=b592c1f562f0da80ce2c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15741e22a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1105b4e2a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/098f7ee2237c/disk-123212f5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/88defebbfc49/vmlinux-123212f5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d5e9343ec16a/bzImage-123212f5.xz

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

general protection fault, probably for non-canonical address 0xdffffc000000001c: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000e0-0x00000000000000e7]
CPU: 1 PID: 5024 Comm: syz-executor280 Not tainted 6.4.0-next-20230707-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:ovl_do_getxattr fs/overlayfs/overlayfs.h:263 [inline]
RIP: 0010:ovl_path_getxattr fs/overlayfs/overlayfs.h:292 [inline]
RIP: 0010:ovl_init_uuid_xattr+0x1f6/0xa90 fs/overlayfs/util.c:695
Code: c1 ea 03 80 3c 02 00 0f 85 54 08 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 74 24 08 48 8d be e0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f2 07 00 00 4c 89 e1 48 8b 86 e0 00 00 00 48 ba
RSP: 0018:ffffc90003aafab8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888014e67c00 RCX: 0000000000000005
RDX: 000000000000001c RSI: 0000000000000000 RDI: 00000000000000e0
RBP: ffff888029c04678 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801927c480
R13: ffff888014e67c79 R14: ffff888014e67c60 R15: 0000000000000000
FS: 0000555556b13300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 0000000022580000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ovl_fill_super+0x1f94/0x5d70 fs/overlayfs/super.c:1437
vfs_get_super+0xea/0x280 fs/super.c:1152
vfs_get_tree+0x8d/0x350 fs/super.c:1519
do_new_mount fs/namespace.c:3335 [inline]
path_mount+0x136e/0x1e70 fs/namespace.c:3662
do_mount fs/namespace.c:3675 [inline]
__do_sys_mount fs/namespace.c:3884 [inline]
__se_sys_mount fs/namespace.c:3861 [inline]
__x64_sys_mount+0x283/0x300 fs/namespace.c:3861
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f60c9bc0b09
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc22c0ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f60c9bc0b09
RDX: 00000000200000c0 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 00007f60c9b84cb0 R08: 0000000020000480 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f60c9b84d40
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ovl_do_getxattr fs/overlayfs/overlayfs.h:263 [inline]
RIP: 0010:ovl_path_getxattr fs/overlayfs/overlayfs.h:292 [inline]
RIP: 0010:ovl_init_uuid_xattr+0x1f6/0xa90 fs/overlayfs/util.c:695
Code: c1 ea 03 80 3c 02 00 0f 85 54 08 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 74 24 08 48 8d be e0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f2 07 00 00 4c 89 e1 48 8b 86 e0 00 00 00 48 ba
RSP: 0018:ffffc90003aafab8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888014e67c00 RCX: 0000000000000005
RDX: 000000000000001c RSI: 0000000000000000 RDI: 00000000000000e0
RBP: ffff888029c04678 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801927c480
R13: ffff888014e67c79 R14: ffff888014e67c60 R15: 0000000000000000
FS: 0000555556b13300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 0000000022580000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: c1 ea 03 shr $0x3,%edx
3: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
7: 0f 85 54 08 00 00 jne 0x861
d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
14: fc ff df
17: 49 8b 74 24 08 mov 0x8(%r12),%rsi
1c: 48 8d be e0 00 00 00 lea 0xe0(%rsi),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 f2 07 00 00 jne 0x826
34: 4c 89 e1 mov %r12,%rcx
37: 48 8b 86 e0 00 00 00 mov 0xe0(%rsi),%rax
3e: 48 rex.W
3f: ba .byte 0xba


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

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

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

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

If the bug is a duplicate of another bug, reply with:
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If you want to undo deduplication, reply with:
#syz undup


2023-07-11 08:54:12

by Amir Goldstein

[permalink] [raw]
Subject: Re: [syzbot] [overlayfs?] general protection fault in ovl_init_uuid_xattr

On Tue, Jul 11, 2023 at 6:32 AM syzbot
<[email protected]> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 123212f53f3e Add linux-next specific files for 20230707
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12353b44a80000
> kernel config: https://syzkaller.appspot.com/x/.config?x=15ec80b62f588543
> dashboard link: https://syzkaller.appspot.com/bug?extid=b592c1f562f0da80ce2c
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15741e22a80000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1105b4e2a80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/098f7ee2237c/disk-123212f5.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/88defebbfc49/vmlinux-123212f5.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/d5e9343ec16a/bzImage-123212f5.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> general protection fault, probably for non-canonical address 0xdffffc000000001c: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x00000000000000e0-0x00000000000000e7]
> CPU: 1 PID: 5024 Comm: syz-executor280 Not tainted 6.4.0-next-20230707-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
> RIP: 0010:ovl_do_getxattr fs/overlayfs/overlayfs.h:263 [inline]
> RIP: 0010:ovl_path_getxattr fs/overlayfs/overlayfs.h:292 [inline]
> RIP: 0010:ovl_init_uuid_xattr+0x1f6/0xa90 fs/overlayfs/util.c:695
> Code: c1 ea 03 80 3c 02 00 0f 85 54 08 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 74 24 08 48 8d be e0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f2 07 00 00 4c 89 e1 48 8b 86 e0 00 00 00 48 ba
> RSP: 0018:ffffc90003aafab8 EFLAGS: 00010202
> RAX: dffffc0000000000 RBX: ffff888014e67c00 RCX: 0000000000000005
> RDX: 000000000000001c RSI: 0000000000000000 RDI: 00000000000000e0
> RBP: ffff888029c04678 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801927c480
> R13: ffff888014e67c79 R14: ffff888014e67c60 R15: 0000000000000000
> FS: 0000555556b13300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000020001000 CR3: 0000000022580000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> ovl_fill_super+0x1f94/0x5d70 fs/overlayfs/super.c:1437
> vfs_get_super+0xea/0x280 fs/super.c:1152
> vfs_get_tree+0x8d/0x350 fs/super.c:1519
> do_new_mount fs/namespace.c:3335 [inline]
> path_mount+0x136e/0x1e70 fs/namespace.c:3662
> do_mount fs/namespace.c:3675 [inline]
> __do_sys_mount fs/namespace.c:3884 [inline]
> __se_sys_mount fs/namespace.c:3861 [inline]
> __x64_sys_mount+0x283/0x300 fs/namespace.c:3861
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f60c9bc0b09
> Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffc22c0ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
> RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f60c9bc0b09
> RDX: 00000000200000c0 RSI: 0000000020000200 RDI: 0000000000000000
> RBP: 00007f60c9b84cb0 R08: 0000000020000480 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f60c9b84d40
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:ovl_do_getxattr fs/overlayfs/overlayfs.h:263 [inline]
> RIP: 0010:ovl_path_getxattr fs/overlayfs/overlayfs.h:292 [inline]
> RIP: 0010:ovl_init_uuid_xattr+0x1f6/0xa90 fs/overlayfs/util.c:695
> Code: c1 ea 03 80 3c 02 00 0f 85 54 08 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 74 24 08 48 8d be e0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 f2 07 00 00 4c 89 e1 48 8b 86 e0 00 00 00 48 ba
> RSP: 0018:ffffc90003aafab8 EFLAGS: 00010202
> RAX: dffffc0000000000 RBX: ffff888014e67c00 RCX: 0000000000000005
> RDX: 000000000000001c RSI: 0000000000000000 RDI: 00000000000000e0
> RBP: ffff888029c04678 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801927c480
> R13: ffff888014e67c79 R14: ffff888014e67c60 R15: 0000000000000000
> FS: 0000555556b13300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000020001000 CR3: 0000000022580000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
> 0: c1 ea 03 shr $0x3,%edx
> 3: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
> 7: 0f 85 54 08 00 00 jne 0x861
> d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
> 14: fc ff df
> 17: 49 8b 74 24 08 mov 0x8(%r12),%rsi
> 1c: 48 8d be e0 00 00 00 lea 0xe0(%rsi),%rdi
> 23: 48 89 fa mov %rdi,%rdx
> 26: 48 c1 ea 03 shr $0x3,%rdx
> * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
> 2e: 0f 85 f2 07 00 00 jne 0x826
> 34: 4c 89 e1 mov %r12,%rcx
> 37: 48 8b 86 e0 00 00 00 mov 0xe0(%rsi),%rax
> 3e: 48 rex.W
> 3f: ba .byte 0xba
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at [email protected].
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs.git
overlayfs-next

2023-07-11 10:15:12

by syzbot

[permalink] [raw]
Subject: Re: [syzbot] [overlayfs?] general protection fault in ovl_init_uuid_xattr

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: [email protected]

Tested on:

commit: 0a3bf81d ovl: auto generate uuid for new overlay files..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs.git overlayfs-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16079b6ca80000
kernel config: https://syzkaller.appspot.com/x/.config?x=150188feee7071a7
dashboard link: https://syzkaller.appspot.com/bug?extid=b592c1f562f0da80ce2c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.