[v6.1] KASAN: use-after-free Read in ocfs2_search_dirblock

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f4f677285b38 Linux 6.1.126
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17586964580000
kernel config: https://syzkaller.appspot.com/x/.config?x=175d65561bbe8acf
dashboard link: https://syzkaller.appspot.com/bug?extid=431bbdbca98058b47a18
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/29acafb07afa/disk-f4f67728.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5cf6e6722b24/vmlinux-f4f67728.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4b92c1bb1642/Image-f4f67728.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+431bbd...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in ocfs2_match fs/ocfs2/dir.c:334 [inline]
BUG: KASAN: use-after-free in ocfs2_search_dirblock+0x22c/0x840 fs/ocfs2/dir.c:367
Read of size 1 at addr ffff0000f84868cb by task syz.4.19/4431

CPU: 0 PID: 4431 Comm: syz.4.19 Not tainted 6.1.126-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:316 [inline]
print_report+0x174/0x4c0 mm/kasan/report.c:427
kasan_report+0xd4/0x130 mm/kasan/report.c:531
__asan_report_load1_noabort+0x2c/0x38 mm/kasan/report_generic.c:348
ocfs2_match fs/ocfs2/dir.c:334 [inline]
ocfs2_search_dirblock+0x22c/0x840 fs/ocfs2/dir.c:367
ocfs2_find_entry_id fs/ocfs2/dir.c:414 [inline]
ocfs2_find_entry+0xf34/0x2620 fs/ocfs2/dir.c:1078
ocfs2_find_files_on_disk+0x130/0x468 fs/ocfs2/dir.c:1982
ocfs2_lookup_ino_from_name+0xb8/0x1d4 fs/ocfs2/dir.c:2004
ocfs2_lookup+0x28c/0xc0c fs/ocfs2/namei.c:122
lookup_open fs/namei.c:3460 [inline]
open_last_lookups fs/namei.c:3550 [inline]
path_openat+0xd3c/0x2548 fs/namei.c:3780
do_filp_open+0x1bc/0x3cc fs/namei.c:3810
do_sys_openat2+0x128/0x3e0 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the physical page:
page:0000000016b29148 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x138486
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003e121c8 fffffc0003e12148 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff0000f8486780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000f8486800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000f8486880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff0000f8486900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000f8486980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: f4f677285b38 Linux 6.1.126
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=12b70ab0580000

kernel config: https://syzkaller.appspot.com/x/.config?x=175d65561bbe8acf
dashboard link: https://syzkaller.appspot.com/bug?extid=431bbdbca98058b47a18
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d46964580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16532ab0580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/29acafb07afa/disk-f4f67728.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5cf6e6722b24/vmlinux-f4f67728.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4b92c1bb1642/Image-f4f67728.gz.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/1684a18e9eb0/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+431bbd...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,0) on (node local, slot 0) with writeback data mode.

==================================================================
BUG: KASAN: use-after-free in ocfs2_match fs/ocfs2/dir.c:334 [inline]
BUG: KASAN: use-after-free in ocfs2_search_dirblock+0x22c/0x840 fs/ocfs2/dir.c:367

Read of size 1 at addr ffff0000e52338cb by task syz-executor169/4305

CPU: 0 PID: 4305 Comm: syz-executor169 Not tainted 6.1.126-syzkaller #0

page:00000000983fb47e refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x125233
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003948d08 fffffc0003948c88 0000000000000000

raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff0000e5233780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000e5233800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000e5233880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff0000e5233900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000e5233980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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