[syzbot] BUG: unable to handle kernel NULL pointer dereference in reiserfs_find_entry

[syzbot <syzbot+4654552e088ed458b10d@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    55be6084c8e0 Merge tag 'timers-core-2022-10-05' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14e8a2c2880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c29b6436e994d72e
dashboard link: https://syzkaller.appspot.com/bug?extid=4654552e088ed458b10d
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/c8f5131ab57d/disk-55be6084.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/77167f226f35/vmlinux-55be6084.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4654552e088ed458b10d@syzkaller.appspotmail.com

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 793df067 P4D 793df067 PUD 7601a067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 25700 Comm: syz-executor.4 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90003c0f158 EFLAGS: 00010246
RAX: 1ffff11010973c1b RBX: ffff888084b9e0d8 RCX: 0000000000040000
RDX: ffffc9000c01a000 RSI: 0000000000000005 RDI: ffff88801f59f098
RBP: ffffc90003c0f2f0 R08: 0000000000000005 R09: ffffffff8222326d
R10: 0000000000000003 R11: ffff888023308000 R12: ffff888083088678
R13: dffffc0000000000 R14: ffff888037621c10 R15: 0000000000000005
FS:  00007feebdc43700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000036ec7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 get_third_component fs/reiserfs/namei.c:196 [inline]
 reiserfs_find_entry+0x253/0x1a10 fs/reiserfs/namei.c:317
 reiserfs_lookup+0x1e3/0x4a0 fs/reiserfs/namei.c:368
 __lookup_slow+0x286/0x3e0 fs/namei.c:1685
 lookup_slow fs/namei.c:1702 [inline]
 lookup_one_unlocked+0x3f8/0x670 fs/namei.c:2772
 ovl_lookup_positive_unlocked fs/overlayfs/namei.c:207 [inline]
 ovl_lookup_single+0x11f/0xa60 fs/overlayfs/namei.c:233
 ovl_lookup_layer+0x44e/0x540 fs/overlayfs/namei.c:320
 ovl_lookup+0xb09/0x2470 fs/overlayfs/namei.c:923
 __lookup_hash+0x115/0x240 fs/namei.c:1601
 do_renameat2+0x58b/0x1400 fs/namei.c:4850
 __do_sys_rename fs/namei.c:4953 [inline]
 __se_sys_rename fs/namei.c:4951 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:4951
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7feebca8b5a9
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feebdc43168 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007feebcbabf80 RCX: 00007feebca8b5a9
RDX: 0000000000000000 RSI: 0000000020000800 RDI: 00000000200007c0
RBP: 00007feebcae6580 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff2dc3b58f R14: 00007feebdc43300 R15: 0000000000022000
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90003c0f158 EFLAGS: 00010246
RAX: 1ffff11010973c1b RBX: ffff888084b9e0d8 RCX: 0000000000040000
RDX: ffffc9000c01a000 RSI: 0000000000000005 RDI: ffff88801f59f098
RBP: ffffc90003c0f2f0 R08: 0000000000000005 R09: ffffffff8222326d
R10: 0000000000000003 R11: ffff888023308000 R12: ffff888083088678
R13: dffffc0000000000 R14: ffff888037621c10 R15: 0000000000000005
FS:  00007feebdc43700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000036ec7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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