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Mon, 13 Oct 2025 03:00:02 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-nilfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <68a82586.a00a0220.33401d.0251.GAE@google.com> <68ecc3e7.a70a0220.b3ac9.0018.GAE@google.com> In-Reply-To: <68ecc3e7.a70a0220.b3ac9.0018.GAE@google.com> From: Ryusuke Konishi Date: Mon, 13 Oct 2025 18:59:45 +0900 X-Gm-Features: AS18NWDHTAsGWZvODheBc1kJzZriUQyKA3xAnTof13KyeFZuiD8P2150oFmETqM Message-ID: Subject: Re: [syzbot] [nilfs?] WARNING in nilfs_rename (2) To: syzbot Cc: linux-nilfs@vger.kernel.org, syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Oct 13, 2025 at 6:23=E2=80=AFPM syzbot wrote: > > syzbot has found a reproducer for the following issue on: > > HEAD commit: 2b763d465239 Add linux-next specific files for 20251010 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=3D1584730458000= 0 > kernel config: https://syzkaller.appspot.com/x/.config?x=3D99cb6b007a888= 9ef > dashboard link: https://syzkaller.appspot.com/bug?extid=3Df6c7e1f1809f235= eeb90 > compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b797= 6-1~exp1~20250708183702.136), Debian LLD 20.1.8 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=3D1191867c580= 000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=3D1384730458000= 0 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/6a00344625c3/dis= k-2b763d46.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/cd34c500f8eb/vmlinu= x-2b763d46.xz > kernel image: https://storage.googleapis.com/syzbot-assets/660905c62cb2/b= zImage-2b763d46.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/25cb8f0127= 0c/mount_0.gz > > IMPORTANT: if you fix the issue, please add the following tag to the comm= it: > Reported-by: syzbot+f6c7e1f1809f235eeb90@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > WARNING: fs/inode.c:417 at drop_nlink+0xc5/0x110 fs/inode.c:417, CPU#0: s= yz.0.217/6748 > Modules linked in: > CPU: 0 UID: 0 PID: 6748 Comm: syz.0.217 Not tainted syzkaller #0 PREEMPT(= full) > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS G= oogle 10/02/2025 > RIP: 0010:drop_nlink+0xc5/0x110 fs/inode.c:417 > Code: 70 07 00 00 be 08 00 00 00 e8 07 da e7 ff f0 48 ff 83 70 07 00 00 5= b 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc e8 dc 26 82 ff 90 <0f> 0b 90 eb 81= 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 5b ff ff ff > RSP: 0018:ffffc9000c52f9d0 EFLAGS: 00010293 > RAX: ffffffff823e1d34 RBX: ffff88805699e008 RCX: ffff888027213c80 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 0000000000000000 R08: ffffffff8f9e1877 R09: 1ffffffff1f3c30e > R10: dffffc0000000000 R11: fffffbfff1f3c30f R12: 1ffff1100ad33c0a > R13: ffff88805699d368 R14: ffff88805699e050 R15: dffffc0000000000 > FS: 00007f06f15f66c0(0000) GS:ffff888125d0b000(0000) knlGS:0000000000000= 000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fa97ff3f000 CR3: 0000000072f60000 CR4: 00000000003526f0 > Call Trace: > > nilfs_rename+0x46a/0x820 fs/nilfs2/namei.c:418 > vfs_rename+0xb34/0xe80 fs/namei.c:5216 > do_renameat2+0x6a2/0xa50 fs/namei.c:5364 > __do_sys_rename fs/namei.c:5411 [inline] > __se_sys_rename fs/namei.c:5409 [inline] > __x64_sys_rename+0x82/0x90 fs/namei.c:5409 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f06f078eec9 > Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f= 7 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 a8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007f06f15f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 > RAX: ffffffffffffffda RBX: 00007f06f09e5fa0 RCX: 00007f06f078eec9 > RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000200000000040 > RBP: 00007f06f0811f91 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007f06f09e6038 R14: 00007f06f09e5fa0 R15: 00007fffd3cbc518 > > > > --- > 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. I have confirmed that this issue can be reproduced in 6.18-rc1 with the reproducer. It is not 100% reproducible, but I was able to reproduce it by enabling the panic_on_warn option and continuing to run the program for a while, so at this point I suspect that it is due to some kind of underlying timing issue. Ryusuke Konishi