Message-ID: <686d5a9f.050a0220.1ffab7.0015.GAE@google.com>
Date: Tue, 08 Jul 2025 10:51:27 -0700
From: syzbot <syzbot+895c23f6917da440ed0d@...kaller.appspotmail.com>
To: brauner@...nel.org, jack@...e.cz, konishi.ryusuke@...il.com, 
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-nilfs@...r.kernel.org, mjguzik@...il.com, 
	syzkaller-bugs@...glegroups.com, viro@...iv.linux.org.uk
Subject: [syzbot] [nilfs?] kernel BUG in may_open (2)

Hello,

syzbot found the following issue on:

HEAD commit:    d7b8f8e20813 Linux 6.16-rc5
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=107e728c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=72aa0474e3c3b9ac
dashboard link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11305582580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10952bd4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/605b3edeb031/disk-d7b8f8e2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a3cb6f3ea4a9/vmlinux-d7b8f8e2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cd9e0c6a9926/bzImage-d7b8f8e2.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/2a7ab270a8da/mount_0.gz

The issue was bisected to:

commit af153bb63a336a7ca0d9c8ef4ca98119c5020030
Author: Mateusz Guzik <mjguzik@...il.com>
Date:   Sun Feb 9 18:55:21 2025 +0000

    vfs: catch invalid modes in may_open()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17f94a8c580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=14054a8c580000
console output: https://syzkaller.appspot.com/x/log.txt?x=10054a8c580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+895c23f6917da440ed0d@...kaller.appspotmail.com
Fixes: af153bb63a33 ("vfs: catch invalid modes in may_open()")

VFS_BUG_ON_INODE(!IS_ANON_FILE(inode)) encountered for inode ffff8880724735b8
------------[ cut here ]------------
kernel BUG at fs/namei.c:3483!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 5842 Comm: syz-executor360 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:may_open+0x4b1/0x4c0 fs/namei.c:3483
Code: 38 c1 0f 8c 1e fd ff ff 4c 89 e7 e8 69 25 ec ff e9 11 fd ff ff e8 9f cd 8a ff 4c 89 f7 48 c7 c6 40 40 99 8b e8 70 cb f2 fe 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc90003f87940 EFLAGS: 00010246
RAX: 000000000000004d RBX: dffffc0000000000 RCX: 158c895b4c6f3300
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000109042 R08: ffffc90003f87667 R09: 1ffff920007f0ecc
R10: dffffc0000000000 R11: fffff520007f0ecd R12: 0000000000000000
R13: ffffffff8e29ca80 R14: ffff8880724735b8 R15: 0000000000000006
FS:  000055555ad6e380(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f084598dd30 CR3: 0000000073c6a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 do_open fs/namei.c:3894 [inline]
 path_openat+0x2d91/0x3830 fs/namei.c:4055
 do_filp_open+0x1fa/0x410 fs/namei.c:4082
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_open fs/open.c:1460 [inline]
 __se_sys_open fs/open.c:1456 [inline]
 __x64_sys_open+0x11e/0x150 fs/open.c:1456
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa1ddded59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcaa4b44f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffa1ddded59
RDX: 0000000000000000 RSI: 0000000000109042 RDI: 0000200000000000
RBP: 00007ffa1de725f0 R08: 000000000001f1b6 R09: 000055555ad6f4c0
R10: 00007ffcaa4b43c0 R11: 0000000000000246 R12: 00007ffcaa4b4520
R13: 00007ffcaa4b4748 R14: 431bde82d7b634db R15: 00007ffa1de2803b
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:may_open+0x4b1/0x4c0 fs/namei.c:3483
Code: 38 c1 0f 8c 1e fd ff ff 4c 89 e7 e8 69 25 ec ff e9 11 fd ff ff e8 9f cd 8a ff 4c 89 f7 48 c7 c6 40 40 99 8b e8 70 cb f2 fe 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc90003f87940 EFLAGS: 00010246
RAX: 000000000000004d RBX: dffffc0000000000 RCX: 158c895b4c6f3300
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000109042 R08: ffffc90003f87667 R09: 1ffff920007f0ecc
R10: dffffc0000000000 R11: fffff520007f0ecd R12: 0000000000000000
R13: ffffffff8e29ca80 R14: ffff8880724735b8 R15: 0000000000000006
FS:  000055555ad6e380(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f084598dd30 CR3: 0000000073c6a000 CR4: 00000000003526f0


---
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 syzkaller@...glegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, 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 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

Powered by blists - more mailing lists