Hello, syzbot found the following issue on: HEAD commit: 40384c840ea1 Linux 6.13-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1768d5e8580000 kernel config: https://syzkaller.appspot.com/x/.config?x=ad7dafcfaa48849c dashboard link: https://syzkaller.appspot.com/bug?extid=8f8fe64a30c50b289a18 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/32ee9cd04555/disk-40384c84.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e7894cd1da27/vmlinux-40384c84.xz kernel image: https://storage.googleapis.com/syzbot-assets/2129df5d769f/bzImage-40384c84.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8f8fe64a30c50b289a18@xxxxxxxxxxxxxxxxxxxxxxxxx syz.2.96: attempt to access beyond end of device loop2: rw=0, sector=161, nr_sectors = 1 limit=64 Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 UID: 0 PID: 6259 Comm: syz.2.96 Not tainted 6.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:exfat_get_dentry_cached+0x11a/0x1b0 fs/exfat/dir.c:727 Code: df 48 89 da 48 c1 ea 03 80 3c 02 00 0f 85 9d 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 1b 48 8d 7b 28 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 61 49 8d 7d 18 48 8b 43 28 48 ba 00 00 00 00 00 fc RSP: 0018:ffffc9000bd8f378 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000009 RDX: 0000000000000005 RSI: ffffffff8270df36 RDI: 0000000000000028 RBP: 0000000000000200 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000009 R11: 0000000000000003 R12: ffffc9000bd8f4a0 R13: ffff88805919c000 R14: 0000000000000009 R15: 0000000000000010 FS: 00007f71995436c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3031cff8 CR3: 000000007b9ce000 CR4: 0000000000350ef0 Call Trace: <TASK> exfat_init_ext_entry+0x1b6/0x3b0 fs/exfat/dir.c:498 exfat_add_entry+0x321/0x7a0 fs/exfat/namei.c:517 exfat_create+0x1cf/0x5c0 fs/exfat/namei.c:565 lookup_open.isra.0+0x1177/0x14c0 fs/namei.c:3649 open_last_lookups fs/namei.c:3748 [inline] path_openat+0x904/0x2d60 fs/namei.c:3984 do_filp_open+0x20c/0x470 fs/namei.c:4014 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_creat fs/open.c:1495 [inline] __se_sys_creat fs/open.c:1489 [inline] __x64_sys_creat+0xcd/0x120 fs/open.c:1489 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: 0033:0x7f7198780849 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7199543058 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f7198946240 RCX: 00007f7198780849 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000e00 RBP: 00007f71987f3986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f7198946240 R15: 00007ffd4aed7f08 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:exfat_get_dentry_cached+0x11a/0x1b0 fs/exfat/dir.c:727 Code: df 48 89 da 48 c1 ea 03 80 3c 02 00 0f 85 9d 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 1b 48 8d 7b 28 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 61 49 8d 7d 18 48 8b 43 28 48 ba 00 00 00 00 00 fc ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 48 89 da mov %rbx,%rdx 3: 48 c1 ea 03 shr $0x3,%rdx 7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) b: 0f 85 9d 00 00 00 jne 0xae 11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 18: fc ff df 1b: 48 8b 1b mov (%rbx),%rbx 1e: 48 8d 7b 28 lea 0x28(%rbx),%rdi 22: 48 89 fa mov %rdi,%rdx 25: 48 c1 ea 03 shr $0x3,%rdx * 29: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2d: 75 61 jne 0x90 2f: 49 8d 7d 18 lea 0x18(%r13),%rdi 33: 48 8b 43 28 mov 0x28(%rbx),%rax 37: 48 rex.W 38: ba 00 00 00 00 mov $0x0,%edx 3d: 00 fc add %bh,%ah --- 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. 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
