Hello, syzbot found the following issue on: HEAD commit: f1fcbaa18b28 Linux 6.4-rc2 git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=114aa029280000 kernel config: https://syzkaller.appspot.com/x/.config?x=6beb6ffe4f59ef2a dashboard link: https://syzkaller.appspot.com/bug?extid=bbb353775d51424087f2 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13dd834e280000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=167ef106280000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/4adf207e9d5e/disk-f1fcbaa1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/9e7cce92f611/vmlinux-f1fcbaa1.xz kernel image: https://storage.googleapis.com/syzbot-assets/cfd911b80f89/bzImage-f1fcbaa1.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/a2583fbaaf14/mount_2.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bbb353775d51424087f2@xxxxxxxxxxxxxxxxxxxxxxxxx erofs: (device loop0): EXPERIMENTAL global deduplication feature in use. Use at your own risk! general protection fault, probably for non-canonical address 0xdffffc0000000019: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf] CPU: 0 PID: 4995 Comm: syz-executor235 Not tainted 6.4.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 RIP: 0010:erofs_bread+0x56/0x6d0 fs/erofs/data.c:38 Code: 48 c1 ea 03 80 3c 02 00 0f 85 15 06 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 23 49 8d bc 24 ca 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 82 05 00 00 RSP: 0018:ffffc900034b7980 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffc900034b7af8 RCX: 0000000000000000 RDX: 0000000000000019 RSI: ffffffff83c1ea5f RDI: 00000000000000ca RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000003f R10: 000000000000000c R11: ffffffff81d50f12 R12: 0000000000000000 R13: 0000000000000001 R14: ffff888019bd4000 R15: ffff888019bd4000 FS: 0000555555bf6300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc664ae0ca0 CR3: 0000000020cc6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> erofs_read_metadata+0xbb/0x490 fs/erofs/super.c:137 erofs_xattr_prefixes_init+0x3b1/0x590 fs/erofs/xattr.c:684 erofs_fc_fill_super+0x1734/0x2a80 fs/erofs/super.c:825 get_tree_bdev+0x44a/0x770 fs/super.c:1303 vfs_get_tree+0x8d/0x350 fs/super.c:1510 do_new_mount fs/namespace.c:3039 [inline] path_mount+0x134b/0x1e40 fs/namespace.c:3369 do_mount fs/namespace.c:3382 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x283/0x300 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc664b09e5a Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd1310be98 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fc664b09e5a RDX: 0000000020000180 RSI: 0000000020000140 RDI: 00007ffd1310bea0 RBP: 00007ffd1310bea0 R08: 00007ffd1310bee0 R09: 00000000000001d4 R10: 0000000001000801 R11: 0000000000000286 R12: 0000000000000005 R13: 0000555555bf62c0 R14: 00007ffd1310bee0 R15: 0000000000000000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:erofs_bread+0x56/0x6d0 fs/erofs/data.c:38 Code: 48 c1 ea 03 80 3c 02 00 0f 85 15 06 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 23 49 8d bc 24 ca 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 82 05 00 00 RSP: 0018:ffffc900034b7980 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffc900034b7af8 RCX: 0000000000000000 RDX: 0000000000000019 RSI: ffffffff83c1ea5f RDI: 00000000000000ca RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000003f R10: 000000000000000c R11: ffffffff81d50f12 R12: 0000000000000000 R13: 0000000000000001 R14: ffff888019bd4000 R15: ffff888019bd4000 FS: 0000555555bf6300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb0e8fdab10 CR3: 0000000020cc6000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- 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 15 06 00 00 jne 0x623 e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 15: fc ff df 18: 4c 8b 23 mov (%rbx),%r12 1b: 49 8d bc 24 ca 00 00 lea 0xca(%r12),%rdi 22: 00 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2e: 48 89 fa mov %rdi,%rdx 31: 83 e2 07 and $0x7,%edx 34: 38 d0 cmp %dl,%al 36: 7f 08 jg 0x40 38: 84 c0 test %al,%al 3a: 0f 85 82 05 00 00 jne 0x5c2 --- 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 bug is already fixed, 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 change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
