[moderation] [jfs?] KASAN: slab-use-after-free Read in txUnlock (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fce2dfa773ce Merge tag 'v7.2-rc3-smb3-client-fixes' of git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12fc6cb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=20c9876b0f77b546
dashboard link: https://syzkaller.appspot.com/bug?extid=72628b4574ea10c3f08e
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-fce2dfa7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1c8b7734ea9f/vmlinux-fce2dfa7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3b9e83087a5/bzImage-fce2dfa7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+72628b...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in txUnlock+0x951/0xde0 fs/jfs/jfs_txnmgr.c:927
Read of size 2 at addr ffff888031a86c98 by task jfsCommit/108

CPU: 0 UID: 0 PID: 108 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
txUnlock+0x951/0xde0 fs/jfs/jfs_txnmgr.c:927
txLazyCommit fs/jfs/jfs_txnmgr.c:2684 [inline]
jfs_lazycommit+0x59f/0xac0 fs/jfs/jfs_txnmgr.c:2735
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

Allocated by task 5328:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4612 [inline]
slab_alloc_node mm/slub.c:4945 [inline]
kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4959
mempool_alloc_noprof+0x1bf/0x300 mm/mempool.c:559
alloc_metapage fs/jfs/jfs_metapage.c:264 [inline]
__get_metapage+0x4ed/0xdf0 fs/jfs/jfs_metapage.c:761
diWrite+0x401/0x1f60 fs/jfs/jfs_imap.c:639
txCommit+0x83a/0x54a0 fs/jfs/jfs_txnmgr.c:1257
__jfs_xattr_set+0x10e/0x170 fs/jfs/xattr.c:943
__vfs_setxattr+0x442/0x480 fs/xattr.c:223
__vfs_setxattr_noperm+0x12a/0x660 fs/xattr.c:257
vfs_setxattr+0x163/0x360 fs/xattr.c:344
do_setxattr fs/xattr.c:662 [inline]
filename_setxattr+0x296/0x630 fs/xattr.c:690
path_setxattrat+0x408/0x450 fs/xattr.c:734
__do_sys_setxattr fs/xattr.c:768 [inline]
__se_sys_setxattr fs/xattr.c:764 [inline]
__x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:764
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 75:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2705 [inline]
slab_free mm/slub.c:6405 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6532
mempool_free+0xec/0x130 mm/mempool.c:704
free_metapage fs/jfs/jfs_metapage.c:280 [inline]
metapage_release_folio+0x462/0x590 fs/jfs/jfs_metapage.c:637
shrink_folio_list+0x2364/0x5330 mm/vmscan.c:1463
evict_folios+0x3821/0x4b40 mm/vmscan.c:4835
try_to_shrink_lruvec+0xb4f/0xed0 mm/vmscan.c:4983
shrink_one+0x233/0x730 mm/vmscan.c:5024
shrink_many mm/vmscan.c:5087 [inline]
lru_gen_shrink_node mm/vmscan.c:5165 [inline]
shrink_node+0x3303/0x3b60 mm/vmscan.c:6154
kswapd_shrink_node mm/vmscan.c:7008 [inline]
balance_pgdat mm/vmscan.c:7186 [inline]
kswapd+0x17b6/0x31c0 mm/vmscan.c:7462
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888031a86c98
which belongs to the cache jfs_mp of size 184
The buggy address is located 0 bytes inside of
freed 184-byte region [ffff888031a86c98, ffff888031a86d50)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31a86
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff8880316b6dc0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 9012459893, free_ts 0
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3294 [inline]
allocate_slab+0x79/0x5e0 mm/slub.c:3408
new_slab mm/slub.c:3454 [inline]
refill_objects+0x2d5/0x350 mm/slub.c:7338
refill_sheaf mm/slub.c:2832 [inline]
__pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4703
alloc_from_pcs mm/slub.c:4801 [inline]
slab_alloc_node mm/slub.c:4933 [inline]
kmem_cache_alloc_noprof+0x382/0x5f0 mm/slub.c:4959
mempool_init_node+0x1f4/0x4f0 mm/mempool.c:259
mempool_create_node_noprof+0xb8/0x150 mm/mempool.c:323
metapage_init+0xed/0x150 fs/jfs/jfs_metapage.c:293
init_jfs_fs+0xfd/0x4e0 fs/jfs/super.c:969
do_one_initcall+0x250/0x870 init/main.c:1347
do_initcall_level+0x10a/0x1a0 init/main.c:1409
do_initcalls+0x59/0xa0 init/main.c:1425
kernel_init_freeable+0x29d/0x3e0 init/main.c:1658
kernel_init+0x1d/0x1d0 init/main.c:1548
page_owner free stack trace missing

Memory state around the buggy address:
ffff888031a86b80: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb
ffff888031a86c00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
>ffff888031a86c80: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888031a86d00: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
ffff888031a86d80: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


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