[syzbot] BUG: unable to handle kernel paging request in path_openat

From: syzbot
Date: Thu Dec 01 2022 - 09:25:46 EST

Hello,

syzbot found the following issue on:

HEAD commit: cf562a45a0d5 Merge tag 'pull-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=147339bb880000
kernel config: https://syzkaller.appspot.com/x/.config?x=8d01b6e3197974dd
dashboard link: https://syzkaller.appspot.com/bug?extid=59a66cac604a6b49ecce
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6a92dc058341/disk-cf562a45.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c320c2307225/vmlinux-cf562a45.xz
kernel image: https://storage.googleapis.com/syzbot-assets/00049e41b3c5/bzImage-cf562a45.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+59a66cac604a6b49ecce@xxxxxxxxxxxxxxxxxxxxxxxxx

REISERFS (device loop4): Using r5 hash to sort names
REISERFS (device loop4): Created .reiserfs_priv - reserved for xattr storage.
BUG: unable to handle page fault for address: fffffbfff8000014
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23ffe4067 P4D 23ffe4067 PUD 23ffe3067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 13823 Comm: syz-executor.4 Not tainted 6.1.0-rc6-syzkaller-00375-gcf562a45a0d5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:__d_entry_type include/linux/dcache.h:385 [inline]
RIP: 0010:d_can_lookup include/linux/dcache.h:400 [inline]
RIP: 0010:d_is_dir include/linux/dcache.h:410 [inline]
RIP: 0010:do_open fs/namei.c:3533 [inline]
RIP: 0010:path_openat+0x213e/0x2df0 fs/namei.c:3714
Code: ff ff e8 05 d2 99 ff 4c 8b 74 24 18 48 8b 44 24 70 42 80 3c 20 00 74 08 4c 89 f7 e8 ac eb ed ff 4d 8b 36 4c 89 f0 48 c1 e8 03 <42> 8a 04 20 84 c0 0f 85 9e 09 00 00 bb 00 00 60 00 41 23 1e bf 00
RSP: 0018:ffffc9000328f920 EFLAGS: 00010a06
RAX: 1ffffffff8000014 RBX: 0000000000000042 RCX: 0000000000040000
RDX: ffffc90003fb2000 RSI: 000000000000500f RDI: 0000000000005010
RBP: ffffc9000328fb50 R08: ffffffff81f0c583 R09: fffffbfff1cebdfe
R10: fffffbfff1cebdfe R11: 1ffffffff1cebdfd R12: dffffc0000000000
R13: ffffc9000328fba0 R14: ffffffffc00000a3 R15: ffffc9000328fda0
FS: 00007f4c5c8c5700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff8000014 CR3: 000000001e588000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
do_filp_open+0x264/0x4f0 fs/namei.c:3741
do_sys_openat2+0x124/0x4e0 fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1337
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4c5ba8c0d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007f4c5c8c5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4c5bbabf80 RCX: 00007f4c5ba8c0d9
RDX: 000000000000275a RSI: 0000000020000140 RDI: ffffffffffffff9c
RBP: 00007f4c5bae7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdd5f5636f R14: 00007f4c5c8c5300 R15: 0000000000022000
</TASK>
Modules linked in:
CR2: fffffbfff8000014
---[ end trace 0000000000000000 ]---
RIP: 0010:__d_entry_type include/linux/dcache.h:385 [inline]
RIP: 0010:d_can_lookup include/linux/dcache.h:400 [inline]
RIP: 0010:d_is_dir include/linux/dcache.h:410 [inline]
RIP: 0010:do_open fs/namei.c:3533 [inline]
RIP: 0010:path_openat+0x213e/0x2df0 fs/namei.c:3714
Code: ff ff e8 05 d2 99 ff 4c 8b 74 24 18 48 8b 44 24 70 42 80 3c 20 00 74 08 4c 89 f7 e8 ac eb ed ff 4d 8b 36 4c 89 f0 48 c1 e8 03 <42> 8a 04 20 84 c0 0f 85 9e 09 00 00 bb 00 00 60 00 41 23 1e bf 00
RSP: 0018:ffffc9000328f920 EFLAGS: 00010a06
RAX: 1ffffffff8000014 RBX: 0000000000000042 RCX: 0000000000040000
RDX: ffffc90003fb2000 RSI: 000000000000500f RDI: 0000000000005010
RBP: ffffc9000328fb50 R08: ffffffff81f0c583 R09: fffffbfff1cebdfe
R10: fffffbfff1cebdfe R11: 1ffffffff1cebdfd R12: dffffc0000000000
R13: ffffc9000328fba0 R14: ffffffffc00000a3 R15: ffffc9000328fda0
FS: 00007f4c5c8c5700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff8000014 CR3: 000000001e588000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 2 bytes skipped:
0: e8 05 d2 99 ff callq 0xff99d20a
5: 4c 8b 74 24 18 mov 0x18(%rsp),%r14
a: 48 8b 44 24 70 mov 0x70(%rsp),%rax
f: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
14: 74 08 je 0x1e
16: 4c 89 f7 mov %r14,%rdi
19: e8 ac eb ed ff callq 0xffedebca
1e: 4d 8b 36 mov (%r14),%r14
21: 4c 89 f0 mov %r14,%rax
24: 48 c1 e8 03 shr $0x3,%rax
* 28: 42 8a 04 20 mov (%rax,%r12,1),%al <-- trapping instruction
2c: 84 c0 test %al,%al
2e: 0f 85 9e 09 00 00 jne 0x9d2
34: bb 00 00 60 00 mov $0x600000,%ebx
39: 41 23 1e and (%r14),%ebx
3c: bf .byte 0xbf


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