[v5.15] general protection fault in direct2indirect

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1fe619a7d252 Linux 5.15.113
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1363f069280000
kernel config: https://syzkaller.appspot.com/x/.config?x=ab36330fd14820aa
dashboard link: https://syzkaller.appspot.com/bug?extid=2b125bbc556ce1c02ad0
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1711b31e280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13009a25280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2d1716ac5a07/disk-1fe619a7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9e9e3ef13603/vmlinux-1fe619a7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/810a025eede3/bzImage-1fe619a7.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/82f9aa8ce77d/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2b125b...@syzkaller.appspotmail.com

REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using r5 hash to sort names
REISERFS (device loop0): using 3.5.x disk format
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
REISERFS warning: reiserfs-5093 is_leaf: item entry count seems wrong *3.5*[2 1 0(1) DIR], item_len 35, item_location 4029, free_space(entry_count) 2
REISERFS error (device loop0): vs-5150 search_by_key: invalid format found in block 532. Fsck?
REISERFS (device loop0): Remounting filesystem read-only
general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 PID: 3645 Comm: syz-executor195 Not tainted 5.15.113-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:reiserfs_node_data fs/reiserfs/reiserfs.h:2184 [inline]
RIP: 0010:item_head fs/reiserfs/reiserfs.h:2200 [inline]
RIP: 0010:tp_item_head fs/reiserfs/reiserfs.h:2226 [inline]
RIP: 0010:direct2indirect+0x8a7/0x1430 fs/reiserfs/tail_conversion.c:119
Code: d8 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 0f b6 04 30 84 c0 0f 85 ea 02 00 00 48 63 1b 49 83 c4 28 4c 89 e0 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 e7 e8 ba 73 b9 ff 4d 8b 34 24 48 8d 1c
RSP: 0018:ffffc900037470a0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 0000000000000000 RCX: ffff88807bbed940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffffc90003747230 R08: ffffffff820fd09d R09: ffffffff820ef579
R10: 0000000000000002 R11: ffff88807bbed940 R12: 0000000000000028
R13: ffffc90003747678 R14: dffffc0000000000 R15: 0000000000000010
FS: 00007f8126159700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f81261f10d0 CR3: 000000001cfdd000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
reiserfs_get_block+0x4e84/0x5390 fs/reiserfs/inode.c:957
__block_write_begin_int+0x60b/0x1650 fs/buffer.c:2012
reiserfs_write_begin+0x346/0x810 fs/reiserfs/inode.c:2790
generic_cont_expand_simple+0x144/0x230 fs/buffer.c:2362
reiserfs_setattr+0x3ff/0xf90 fs/reiserfs/inode.c:3319
notify_change+0xd4d/0x1000 fs/attr.c:488
do_truncate+0x21c/0x300 fs/open.c:65
do_sys_ftruncate+0x2eb/0x390 fs/open.c:193
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+0x61/0xcb
RIP: 0033:0x7f81261ade69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 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:00007f8126159208 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f81262337a8 RCX: 00007f81261ade69
RDX: 00007f81261ade69 RSI: 0000000000000f88 RDI: 0000000000000004
RBP: 00007f81262337a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f81262337ac
R13: 00007ffc06c9f34f R14: 00007f8126159300 R15: 0000000000022000
</TASK>
Modules linked in:
---[ end trace 2281bc7642c9781c ]---
RIP: 0010:reiserfs_node_data fs/reiserfs/reiserfs.h:2184 [inline]
RIP: 0010:item_head fs/reiserfs/reiserfs.h:2200 [inline]
RIP: 0010:tp_item_head fs/reiserfs/reiserfs.h:2226 [inline]
RIP: 0010:direct2indirect+0x8a7/0x1430 fs/reiserfs/tail_conversion.c:119
Code: d8 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 0f b6 04 30 84 c0 0f 85 ea 02 00 00 48 63 1b 49 83 c4 28 4c 89 e0 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 e7 e8 ba 73 b9 ff 4d 8b 34 24 48 8d 1c
RSP: 0018:ffffc900037470a0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 0000000000000000 RCX: ffff88807bbed940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffffc90003747230 R08: ffffffff820fd09d R09: ffffffff820ef579
R10: 0000000000000002 R11: ffff88807bbed940 R12: 0000000000000028
R13: ffffc90003747678 R14: dffffc0000000000 R15: 0000000000000010
FS: 00007f8126159700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f811df23000 CR3: 000000001cfdd000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 48 c1 e8 03 shr $0x3,%rax
4: 49 be 00 00 00 00 00 movabs $0xdffffc0000000000,%r14
b: fc ff df
e: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax
13: 84 c0 test %al,%al
15: 0f 85 ea 02 00 00 jne 0x305
1b: 48 63 1b movslq (%rbx),%rbx
1e: 49 83 c4 28 add $0x28,%r12
22: 4c 89 e0 mov %r12,%rax
25: 48 c1 e8 03 shr $0x3,%rax
* 29: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 e7 mov %r12,%rdi
33: e8 ba 73 b9 ff callq 0xffb973f2
38: 4d 8b 34 24 mov (%r12),%r14
3c: 48 rex.W
3d: 8d .byte 0x8d
3e: 1c .byte 0x1c


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