Re: [syzbot] [ocfs2?] KASAN: use-after-free Read in ocfs2_listxattr

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in ocfs2_listxattr

On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted.
OCFS2: File system is now read-only.
==================================================================
BUG: KASAN: use-after-free in ocfs2_xattr_get_type fs/ocfs2/ocfs2_fs.h:1114 [inline]
BUG: KASAN: use-after-free in ocfs2_xattr_list_entries fs/ocfs2/xattr.c:934 [inline]
BUG: KASAN: use-after-free in ocfs2_xattr_ibody_list fs/ocfs2/xattr.c:982 [inline]
BUG: KASAN: use-after-free in ocfs2_listxattr+0x408/0xa74 fs/ocfs2/xattr.c:1044
Read of size 1 at addr ffff0000e76a4007 by task syz.0.20/7236

CPU: 1 UID: 0 PID: 7236 Comm: syz.0.20 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xa8/0x238 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:482
 kasan_report+0xb0/0x110 mm/kasan/report.c:595
 __asan_report_load1_noabort+0x20/0x2c mm/kasan/report_generic.c:378
 ocfs2_xattr_get_type fs/ocfs2/ocfs2_fs.h:1114 [inline]
 ocfs2_xattr_list_entries fs/ocfs2/xattr.c:934 [inline]
 ocfs2_xattr_ibody_list fs/ocfs2/xattr.c:982 [inline]
 ocfs2_listxattr+0x408/0xa74 fs/ocfs2/xattr.c:1044
 vfs_listxattr+0xc0/0x128 fs/xattr.c:493
 ovl_listxattr+0xd8/0x49c fs/overlayfs/xattrs.c:123
 vfs_listxattr fs/xattr.c:493 [inline]
 listxattr+0x10c/0x380 fs/xattr.c:924
 filename_listxattr fs/xattr.c:958 [inline]
 path_listxattrat+0x15c/0x33c fs/xattr.c:988
 __do_sys_listxattr fs/xattr.c:1001 [inline]
 __se_sys_listxattr fs/xattr.c:998 [inline]
 __arm64_sys_listxattr+0x84/0x98 fs/xattr.c:998
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffb9581 pfn:0x1276a4
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffdffc3a50548 fffffdffc39dab88 0000000000000000
raw: 0000000ffffb9581 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e76a3f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000e76a3f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000e76a4000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000e76a4080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e76a4100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


Tested on:

commit:         e424ed99 Merge remote-tracking branch 'will/for-next/p..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=12f30658580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b8b659f0cab27b22
dashboard link: https://syzkaller.appspot.com/bug?extid=ab0ad25088673470d2d9
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1566f17c580000