[moderation] [gfs2?] KASAN: slab-use-after-free Read in gfs2_ail_empty_tr

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 62085877ae65 Merge tag 'kbuild-fixes-6.19-2' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15e9d05a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e2e5d7c9c1e01cf4
dashboard link: https://syzkaller.appspot.com/bug?extid=a0cd09c39dbcab3f29f8
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
CC: [agru...@redhat.com gf...@lists.linux.dev linux-...@vger.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-62085877.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3e9052cff629/vmlinux-62085877.xz
kernel image: https://storage.googleapis.com/syzbot-assets/68822cbf7682/bzImage-62085877.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a0cd09...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62
Read of size 8 at addr ffff88801f9d7b30 by task kworker/0:4/5326

CPU: 0 UID: 0 PID: 5326 Comm: kworker/0:4 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
Workqueue: events gfs2_withdraw_func
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xba/0x230 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
__list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62
__list_del_entry_valid include/linux/list.h:132 [inline]
__list_del_entry include/linux/list.h:223 [inline]
list_del_init include/linux/list.h:295 [inline]
gfs2_remove_from_ail fs/gfs2/log.c:79 [inline]
gfs2_ail_empty_tr+0x165/0x2f0 fs/gfs2/log.c:287
gfs2_ail_drain+0x8f/0x360 fs/gfs2/log.c:944
do_withdraw+0x115/0x2f0 fs/gfs2/util.c:128
gfs2_withdraw_func+0x2f3/0x430 fs/gfs2/util.c:-1
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>

Allocated by task 5334:
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:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x370/0x6e0 mm/slub.c:5270
gfs2_glock_get+0x27b/0xf40 fs/gfs2/glock.c:1097
gfs2_create_inode+0xd1f/0x1630 fs/gfs2/inode.c:828
gfs2_mkdir+0x9f/0xd0 fs/gfs2/inode.c:1352
vfs_mkdir+0x511/0x5b0 fs/namei.c:5139
do_mkdirat+0x27d/0x4b0 fs/namei.c:5173
__do_sys_mkdirat fs/namei.c:5195 [inline]
__se_sys_mkdirat fs/namei.c:5193 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5333:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 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:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kmem_cache_free+0x195/0x610 mm/slub.c:6785
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0xc9e/0x1750 kernel/rcu/tree.c:2857
handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
crypto_acomp_unlock_stream_bh include/crypto/internal/acompress.h:200 [inline]
scomp_acomp_comp_decomp+0x73a/0xa00 crypto/scompress.c:259
crypto_acomp_decompress+0x4b3/0xbe0 crypto/acompress.c:303
zswap_decompress+0x522/0xac0 mm/zswap.c:967
zswap_load+0x2f1/0x4c0 mm/zswap.c:1627
swap_read_folio+0x6a3/0x25d0 mm/page_io.c:637
swap_cluster_readahead+0x37a/0x680 mm/swap_state.c:652
swapin_readahead+0x196/0xc50 mm/swap_state.c:821
do_swap_page+0x4d4/0x5e20 mm/memory.c:4756
handle_pte_fault mm/memory.c:6279 [inline]
__handle_mm_fault mm/memory.c:6414 [inline]
handle_mm_fault+0x12d2/0x32a0 mm/memory.c:6583
do_user_addr_fault+0xa73/0x1360 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3119 [inline]
call_rcu+0xee/0x890 kernel/rcu/tree.c:3239
gfs2_glock_free+0x3c/0xa0 fs/gfs2/glock.c:151
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Second to last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
insert_work+0x3d/0x330 kernel/workqueue.c:2180
__queue_work+0xccf/0xf90 kernel/workqueue.c:2335
queue_delayed_work_on+0x11a/0x1d0 kernel/workqueue.c:2555
queue_delayed_work include/linux/workqueue.h:684 [inline]
gfs2_glock_queue_work fs/gfs2/glock.c:223 [inline]
do_xmote+0x514/0x750 fs/gfs2/glock.c:738
glock_work_func+0x2a8/0x580 fs/gfs2/glock.c:1010
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

The buggy address belongs to the object at ffff88801f9d7a18
which belongs to the cache gfs2_glock(aspace) of size 1224
The buggy address is located 280 bytes inside of
freed 1224-byte region [ffff88801f9d7a18, ffff88801f9d7ee0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f9d4
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888031ed08c0 dead000000000122 0000000000000000
raw: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff888031ed08c0 dead000000000122 0000000000000000
head: 0000000000000000 00000000000c000c 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00007e7501 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5334, tgid 5333 (syz.0.0), ts 75747997125, free_ts 75701887451
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab+0x86/0x3a0 mm/slub.c:3248
new_slab mm/slub.c:3302 [inline]
___slab_alloc+0xd82/0x1760 mm/slub.c:4656
__slab_alloc+0x65/0x100 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
kmem_cache_alloc_noprof+0x3fe/0x6e0 mm/slub.c:5270
gfs2_glock_get+0x27b/0xf40 fs/gfs2/glock.c:1097
gfs2_inode_lookup+0x29f/0xc50 fs/gfs2/inode.c:149
gfs2_lookup_root fs/gfs2/ops_fstype.c:426 [inline]
init_sb+0xa5a/0x12f0 fs/gfs2/ops_fstype.c:495
gfs2_fill_super+0x16d6/0x21d0 fs/gfs2/ops_fstype.c:1217
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1691
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x329/0xa50 fs/namespace.c:3712
page last free pid 5334 tgid 5333 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0xbb0/0xd10 mm/page_alloc.c:2973
stack_depot_save_flags+0x40e/0x810 lib/stackdepot.c:727
kasan_save_stack mm/kasan/common.c:58 [inline]
kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5657 [inline]
__kmalloc_noprof+0x40c/0x7e0 mm/slub.c:5669
kmalloc_noprof include/linux/slab.h:961 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
__alloc_workqueue+0x104/0x1b80 kernel/workqueue.c:5717
alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5820
gfs2_fill_super+0x1318/0x21d0 fs/gfs2/ops_fstype.c:1188
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1691
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x329/0xa50 fs/namespace.c:3712
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff88801f9d7a00: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801f9d7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801f9d7b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801f9d7b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801f9d7c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


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