Hello, syzbot found the following issue on: HEAD commit: 69e858e0b8b2 Merge tag 'uml-for-linus-6.14-rc1' of git://g.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=11bfc518580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d1a6d4df5fcc342f dashboard link: https://syzkaller.appspot.com/bug?extid=a9c0867e4d1dd0c7ab19 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=125d0eb0580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13a595f8580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a4b4612f419c/disk-69e858e0.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/07abf7c78a98/vmlinux-69e858e0.xz kernel image: https://storage.googleapis.com/syzbot-assets/085b44906cce/bzImage-69e858e0.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/0e8d208f30b1/mount_0.gz The issue was bisected to: commit 30d61efe118cad1a73ad2ad66a3298e4abdf9f41 Author: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Date: Mon Jan 6 02:33:17 2025 +0000 9p: fix ->rename_sem exclusion bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1050fddf980000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1250fddf980000 console output: https://syzkaller.appspot.com/x/log.txt?x=1450fddf980000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a9c0867e4d1dd0c7ab19@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 30d61efe118c ("9p: fix ->rename_sem exclusion") UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000) Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 0 UID: 0 PID: 5832 Comm: syz-executor165 Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__d_unalias fs/dcache.c:2969 [inline] RIP: 0010:d_splice_alias+0x9cd/0xf30 fs/dcache.c:3037 Code: 48 c1 ea 03 80 3c 02 00 0f 85 4e 05 00 00 49 8b 85 70 ff ff ff 48 ba 00 00 00 00 00 fc ff df 48 8d 78 68 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 14 05 00 00 48 8b 40 68 48 85 c0 74 31 48 89 44 RSP: 0018:ffffc90003667c18 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffff88807dbd7318 RCX: 000000000000000d RDX: dffffc0000000000 RSI: ffffffff82348f0c RDI: 0000000000000068 RBP: ffff8880754107b8 R08: 0000000000000000 R09: ffffed100f23d67a R10: ffff8880791eb3d3 R11: 0000000000000032 R12: ffff8880791eb318 R13: ffff8880791eafd8 R14: ffff8880791eaeb0 R15: ffff8880791eaf48 FS: 0000555581642380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe875be000 CR3: 0000000076b7a000 CR4: 0000000000350ef0 Call Trace: <TASK> udf_lookup+0x191/0x240 fs/udf/namei.c:130 lookup_one_qstr_excl+0x120/0x190 fs/namei.c:1693 do_rmdir+0x247/0x410 fs/namei.c:4444 __do_sys_rmdir fs/namei.c:4474 [inline] __se_sys_rmdir fs/namei.c:4472 [inline] __x64_sys_rmdir+0xc5/0x110 fs/namei.c:4472 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9ee0142d99 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:00007ffe875bd248 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 6f72746e6f632f2e RCX: 00007f9ee0142d99 RDX: 00007f9ee0142d99 RSI: 00007f9ee0142d99 RDI: 0000000020000100 RBP: 00007f9ee01b75f0 R08: 00005555816434c0 R09: 00005555816434c0 R10: 00005555816434c0 R11: 0000000000000246 R12: 00007ffe875bd270 R13: 00007ffe875bd498 R14: 431bde82d7b634db R15: 00007f9ee018c03b </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__d_unalias fs/dcache.c:2969 [inline] RIP: 0010:d_splice_alias+0x9cd/0xf30 fs/dcache.c:3037 Code: 48 c1 ea 03 80 3c 02 00 0f 85 4e 05 00 00 49 8b 85 70 ff ff ff 48 ba 00 00 00 00 00 fc ff df 48 8d 78 68 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 14 05 00 00 48 8b 40 68 48 85 c0 74 31 48 89 44 RSP: 0018:ffffc90003667c18 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffff88807dbd7318 RCX: 000000000000000d RDX: dffffc0000000000 RSI: ffffffff82348f0c RDI: 0000000000000068 RBP: ffff8880754107b8 R08: 0000000000000000 R09: ffffed100f23d67a R10: ffff8880791eb3d3 R11: 0000000000000032 R12: ffff8880791eb318 R13: ffff8880791eafd8 R14: ffff8880791eaeb0 R15: ffff8880791eaf48 FS: 0000555581642380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe875be000 CR3: 0000000076b7a000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 48 c1 ea 03 shr $0x3,%rdx 4: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 8: 0f 85 4e 05 00 00 jne 0x55c e: 49 8b 85 70 ff ff ff mov -0x90(%r13),%rax 15: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 1c: fc ff df 1f: 48 8d 78 68 lea 0x68(%rax),%rdi 23: 48 89 f9 mov %rdi,%rcx 26: 48 c1 e9 03 shr $0x3,%rcx * 2a: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) <-- trapping instruction 2e: 0f 85 14 05 00 00 jne 0x548 34: 48 8b 40 68 mov 0x68(%rax),%rax 38: 48 85 c0 test %rax,%rax 3b: 74 31 je 0x6e 3d: 48 rex.W 3e: 89 .byte 0x89 3f: 44 rex.R --- 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@xxxxxxxxxxxxxxxx. 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
