Hello, syzbot found the following issue on: HEAD commit: f486c8aa16b8 Add linux-next specific files for 20241128 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=1549f530580000 kernel config: https://syzkaller.appspot.com/x/.config?x=e348a4873516af92 dashboard link: https://syzkaller.appspot.com/bug?extid=6f6c9397e0078ef60bce compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1443ef5f980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1349f530580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/beb58ebb63cf/disk-f486c8aa.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b241b5609e64/vmlinux-f486c8aa.xz kernel image: https://storage.googleapis.com/syzbot-assets/c9d817f665f2/bzImage-f486c8aa.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/792711885a74/mount_0.gz The issue was bisected to: commit 8a3f5711ad74db9881b289a6e34d7f3b700df720 Author: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx> Date: Thu Sep 12 08:57:06 2024 +0000 exfat: reduce FAT chain traversal bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1145cf78580000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1345cf78580000 console output: https://syzkaller.appspot.com/x/log.txt?x=1545cf78580000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6f6c9397e0078ef60bce@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 8a3f5711ad74 ("exfat: reduce FAT chain traversal") syz-executor166: attempt to access beyond end of device loop3: rw=524288, sector=167, nr_sectors = 1 limit=64 syz-executor166: attempt to access beyond end of device loop3: rw=0, sector=161, nr_sectors = 1 limit=64 Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 UID: 0 PID: 5890 Comm: syz-executor166 Not tainted 6.12.0-next-20241128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:exfat_get_dentry_cached fs/exfat/dir.c:727 [inline] RIP: 0010:exfat_init_ext_entry+0x3fd/0x990 fs/exfat/dir.c:498 Code: 48 98 49 8d 1c c6 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 01 26 89 ff 48 8b 1b 48 83 c3 28 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 e4 25 89 ff 4c 8b 33 43 80 7c 3d RSP: 0018:ffffc900041ff318 EFLAGS: 00010206 RAX: 0000000000000005 RBX: 0000000000000028 RCX: 0000000000000009 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000020 RBP: 0000000000000200 R08: ffffffff8281406f R09: 0000000000000002 R10: ffff88805d092022 R11: ffffed100ba12407 R12: ffffc900041ff700 R13: 1ffff9200083fee0 R14: ffffc900041ff710 R15: dffffc0000000000 FS: 00007fb6d86536c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb6d8653d58 CR3: 000000002fc0c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> exfat_add_entry+0x529/0xaa0 fs/exfat/namei.c:517 exfat_create+0x1c7/0x570 fs/exfat/namei.c:565 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 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+0x123/0x170 fs/open.c:1489 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb6d86c4099 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1b 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb6d8653218 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fb6d87534b8 RCX: 00007fb6d86c4099 RDX: 00007fb6d869bc26 RSI: 0000000000000000 RDI: 0000000020000e00 RBP: 00007fb6d87534b0 R08: 00007ffed34fd087 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb6d8718d84 R13: 00007fb6d8717880 R14: 0032656c69662f2e R15: 6f6f6c2f7665642f </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:exfat_get_dentry_cached fs/exfat/dir.c:727 [inline] RIP: 0010:exfat_init_ext_entry+0x3fd/0x990 fs/exfat/dir.c:498 Code: 48 98 49 8d 1c c6 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 01 26 89 ff 48 8b 1b 48 83 c3 28 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 e4 25 89 ff 4c 8b 33 43 80 7c 3d RSP: 0018:ffffc900041ff318 EFLAGS: 00010206 RAX: 0000000000000005 RBX: 0000000000000028 RCX: 0000000000000009 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000020 RBP: 0000000000000200 R08: ffffffff8281406f R09: 0000000000000002 R10: ffff88805d092022 R11: ffffed100ba12407 R12: ffffc900041ff700 R13: 1ffff9200083fee0 R14: ffffc900041ff710 R15: dffffc0000000000 FS: 00007fb6d86536c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bc85806ca8 CR3: 000000002fc0c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 98 cltq 2: 49 8d 1c c6 lea (%r14,%rax,8),%rbx 6: 48 89 d8 mov %rbx,%rax 9: 48 c1 e8 03 shr $0x3,%rax d: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) 12: 74 08 je 0x1c 14: 48 89 df mov %rbx,%rdi 17: e8 01 26 89 ff call 0xff89261d 1c: 48 8b 1b mov (%rbx),%rbx 1f: 48 83 c3 28 add $0x28,%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 e4 25 89 ff call 0xff89261d 39: 4c 8b 33 mov (%rbx),%r14 3c: 43 rex.XB 3d: 80 .byte 0x80 3e: 7c 3d jl 0x7d --- 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
