Re: [syzbot] [v9fs?] WARNING in v9fs_begin_writeback

[syzbot <syzbot+0b74d367d6e80661d6df@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: wild-memory-access Read in v9fs_dir_release

==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: wild-memory-access in _test_bit_acquire include/asm-generic/bitops/instrumented-non-atomic.h:153 [inline]
BUG: KASAN: wild-memory-access in wait_on_bit_timeout include/linux/wait_bit.h:126 [inline]
BUG: KASAN: wild-memory-access in v9fs_dir_release+0x5b6/0x710 fs/9p/vfs_dir.c:225
Read of size 8 at addr 1fff8880330d80c8 by task syz.0.15/5886

CPU: 3 UID: 0 PID: 5886 Comm: syz.0.15 Not tainted 6.11.0-rc1-syzkaller-00154-gc0ecd6388360-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit_acquire include/asm-generic/bitops/instrumented-non-atomic.h:153 [inline]
 wait_on_bit_timeout include/linux/wait_bit.h:126 [inline]
 v9fs_dir_release+0x5b6/0x710 fs/9p/vfs_dir.c:225
 __fput+0x408/0xbb0 fs/file_table.c:422
 task_work_run+0x14e/0x250 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xaa3/0x2bb0 kernel/exit.c:882
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031
 get_signal+0x25fd/0x2770 kernel/signal.c:2917
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310
 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+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb473773b9
Code: Unable to access opcode bytes at 0x7fbb4737738f.
RSP: 002b:00007fbb4807f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fbb47505f88 RCX: 00007fbb473773b9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fbb47505f8c
RBP: 00007fbb47505f80 R08: 00007fbb48080080 R09: 00007fbb4807f6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbb47505f8c
R13: 000000000000000b R14: 00007fff1cf6dc20 R15: 00007fff1cf6dd08
 </TASK>
==================================================================


Tested on:

commit:         c0ecd638 Merge tag 'pci-v6.11-fixes-1' of git://git.ke..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=15b3bd23980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8da8b059e43c5370
dashboard link: https://syzkaller.appspot.com/bug?extid=0b74d367d6e80661d6df
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15702291980000