[syzbot] [jfs?] KASAN: null-ptr-deref Read in txBegin

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    82eac0c830b7 Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=108c3220c80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=42ba4da8e1e6af9f
dashboard link: https://syzkaller.appspot.com/bug?extid=f1faa20eec55e0c8644c
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=12dea55f480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/da7d342f68c6/disk-82eac0c8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bc04dc7d5c40/vmlinux-82eac0c8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9cbbc3b0e69a/bzImage-82eac0c8.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/40deef8f8496/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f1faa20eec55e0c8644c@xxxxxxxxxxxxxxxxxxxxxxxxx

read_mapping_page failed!
ERROR: (device loop0): txCommit: 
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:72 [inline]
BUG: KASAN: null-ptr-deref in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: null-ptr-deref in txBegin+0x131/0x6c0 fs/jfs/jfs_txnmgr.c:366
Read of size 8 at addr 0000000000000040 by task syz-executor.0/5172

CPU: 0 PID: 5172 Comm: syz-executor.0 Not tainted 6.2.0-rc8-syzkaller-00019-g82eac0c830b7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_report+0xe6/0x4f0 mm/kasan/report.c:420
 kasan_report+0x13a/0x170 mm/kasan/report.c:517
 kasan_check_range+0x283/0x290 mm/kasan/generic.c:189
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 txBegin+0x131/0x6c0 fs/jfs/jfs_txnmgr.c:366
 jfs_link+0x1ac/0x5e0 fs/jfs/namei.c:802
 vfs_link+0x662/0x810 fs/namei.c:4529
 do_linkat+0x5b4/0x9d0 fs/namei.c:4600
 __do_sys_linkat fs/namei.c:4628 [inline]
 __se_sys_linkat fs/namei.c:4625 [inline]
 __x64_sys_linkat+0xdd/0xf0 fs/namei.c:4625
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ff38288c0f9
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:00007ff383575168 EFLAGS: 00000246 ORIG_RAX: 0000000000000109
RAX: ffffffffffffffda RBX: 00007ff3829abf80 RCX: 00007ff38288c0f9
RDX: 0000000000000004 RSI: 0000000020000040 RDI: 0000000000000004
RBP: 00007ff3828e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe4ad3d6bf R14: 00007ff383575300 R15: 0000000000022000
 </TASK>
==================================================================


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