[moderation] [jfs?] KASAN: null-ptr-deref Write in jfs_release

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2d5404caa8c7 Linux 6.12-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=165101a7980000
kernel config: https://syzkaller.appspot.com/x/.config?x=1503500c6f615d24
dashboard link: https://syzkaller.appspot.com/bug?extid=af95893e8a7b60e0ae1a
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [jfs-dis...@lists.sourceforge.net linux-...@vger.kernel.org sha...@kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a2d329b82126/disk-2d5404ca.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/37a04ca225dd/vmlinux-2d5404ca.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4f837ce9d9dc/bzImage-2d5404ca.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+af9589...@syzkaller.appspotmail.com

read_mapping_page failed!
jfs_mount_rw: dbMount failed!
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: null-ptr-deref in atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
BUG: KASAN: null-ptr-deref in jfs_release+0x10b/0x1a0 fs/jfs/file.c:80
Write of size 4 at addr 00000000000004e0 by task syz.5.95/6688

CPU: 0 UID: 0 PID: 6688 Comm: syz.5.95 Not tainted 6.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_report+0xe8/0x550 mm/kasan/report.c:491
kasan_report+0x143/0x180 mm/kasan/report.c:601
kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
jfs_release+0x10b/0x1a0 fs/jfs/file.c:80
__fput+0x23f/0x880 fs/file_table.c:431
task_work_run+0x24f/0x310 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0xa2f/0x28e0 kernel/exit.c:939
do_group_exit+0x207/0x2c0 kernel/exit.c:1088
get_signal+0x16a3/0x1740 kernel/signal.c:2918
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f86d1f7feba
Code: Unable to access opcode bytes at 0x7f86d1f7fe90.
RSP: 002b:00007f86d2debe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffb RBX: 00007f86d2debef0 RCX: 00007f86d1f7feba
RDX: 0000000020000f40 RSI: 0000000020000140 RDI: 0000000000000000
RBP: 0000000020000f40 R08: 00007f86d2debef0 R09: 0000000001a4a438
R10: 0000000001a4a438 R11: 0000000000000246 R12: 0000000020000140
R13: 00007f86d2debeb0 R14: 0000000000000000 R15: 00000000200008c0
</TASK>
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.