[moderation] [gfs2?] KASAN: slab-use-after-free Read in gfs2_release_folio

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d7b8f8e20813 Linux 6.16-rc5
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14c54a8c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f6cfc97245100778
dashboard link: https://syzkaller.appspot.com/bug?extid=bb56b2c14bb9cd927e85
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
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-d7b8f8e2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/88e0e9607487/vmlinux-d7b8f8e2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c0e31868d902/bzImage-d7b8f8e2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bb56b2...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
Read of size 1 at addr ffff888032f1cbe0 by task kswapd0/73

CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full)
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_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xd2/0x2b0 mm/kasan/report.c:521
kasan_report+0x118/0x150 mm/kasan/report.c:634
__kasan_check_byte+0x2a/0x40 mm/kasan/common.c:557
kasan_check_byte include/linux/kasan.h:399 [inline]
lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5845
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
gfs2_log_lock fs/gfs2/log.h:32 [inline]
gfs2_release_folio+0x10c/0x570 fs/gfs2/aops.c:669
shrink_folio_list+0x2113/0x4e90 mm/vmscan.c:1518
evict_folios+0x4447/0x5500 mm/vmscan.c:4731
try_to_shrink_lruvec+0x705/0x990 mm/vmscan.c:4892
shrink_one+0x21b/0x7c0 mm/vmscan.c:4937
shrink_many mm/vmscan.c:5000 [inline]
lru_gen_shrink_node mm/vmscan.c:5078 [inline]
shrink_node+0x314e/0x3760 mm/vmscan.c:6060
kswapd_shrink_node mm/vmscan.c:6911 [inline]
balance_pgdat mm/vmscan.c:7094 [inline]
kswapd+0x147c/0x2830 mm/vmscan.c:7359
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

Allocated by task 5341:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
init_sbd fs/gfs2/ops_fstype.c:78 [inline]
gfs2_fill_super+0x11c/0x20e0 fs/gfs2/ops_fstype.c:1128
get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
vfs_get_tree+0x92/0x2b0 fs/super.c:1804
do_new_mount+0x24a/0xa40 fs/namespace.c:3902
do_mount fs/namespace.c:4239 [inline]
__do_sys_mount fs/namespace.c:4450 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4427
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5341:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2381 [inline]
slab_free mm/slub.c:4643 [inline]
kfree+0x18e/0x440 mm/slub.c:4842
free_sbd fs/gfs2/ops_fstype.c:71 [inline]
gfs2_fill_super+0x153d/0x20e0 fs/gfs2/ops_fstype.c:1319
get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1335
vfs_get_tree+0x92/0x2b0 fs/super.c:1804
do_new_mount+0x24a/0xa40 fs/namespace.c:3902
do_mount fs/namespace.c:4239 [inline]
__do_sys_mount fs/namespace.c:4450 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4427
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888032f1c000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 3040 bytes inside of
freed 8192-byte region [ffff888032f1c000, ffff888032f1e000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32f18
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801a442280 0000000000000000 0000000000000001
raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801a442280 0000000000000000 0000000000000001
head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000
head: 04fff00000000003 ffffea0000cbc601 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5316, tgid 5316 (sh), ts 72110942834, free_ts 72110090224
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
prep_new_page mm/page_alloc.c:1712 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
alloc_slab_page mm/slub.c:2451 [inline]
allocate_slab+0x8a/0x3b0 mm/slub.c:2619
new_slab mm/slub.c:2673 [inline]
___slab_alloc+0xbfc/0x1480 mm/slub.c:3859
__slab_alloc mm/slub.c:3949 [inline]
__slab_alloc_node mm/slub.c:4024 [inline]
slab_alloc_node mm/slub.c:4185 [inline]
__kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4354
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
tomoyo_init_log+0x111f/0x1f70 security/tomoyo/audit.c:264
tomoyo_supervisor+0x340/0x1480 security/tomoyo/common.c:2198
tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
tomoyo_env_perm+0x149/0x1e0 security/tomoyo/environ.c:63
tomoyo_environ security/tomoyo/domain.c:672 [inline]
tomoyo_find_next_domain+0x15cf/0x1aa0 security/tomoyo/domain.c:888
tomoyo_bprm_check_security+0x11c/0x180 security/tomoyo/tomoyo.c:102
security_bprm_check+0x89/0x270 security/security.c:1302
search_binary_handler fs/exec.c:1660 [inline]
exec_binprm fs/exec.c:1702 [inline]
bprm_execve+0x8ee/0x1450 fs/exec.c:1754
do_execveat_common+0x510/0x6a0 fs/exec.c:1860
do_execve fs/exec.c:1934 [inline]
__do_sys_execve fs/exec.c:2010 [inline]
__se_sys_execve fs/exec.c:2005 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2005
page last free pid 5316 tgid 5316 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
__slab_free+0x326/0x400 mm/slub.c:4554
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4148 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
__do_kmalloc_node mm/slub.c:4327 [inline]
__kmalloc_noprof+0x224/0x4f0 mm/slub.c:4340
kmalloc_noprof include/linux/slab.h:909 [inline]
tomoyo_add_entry security/tomoyo/common.c:2132 [inline]
tomoyo_supervisor+0xbd5/0x1480 security/tomoyo/common.c:2204
tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
tomoyo_env_perm+0x149/0x1e0 security/tomoyo/environ.c:63
tomoyo_environ security/tomoyo/domain.c:672 [inline]
tomoyo_find_next_domain+0x15cf/0x1aa0 security/tomoyo/domain.c:888
tomoyo_bprm_check_security+0x11c/0x180 security/tomoyo/tomoyo.c:102
security_bprm_check+0x89/0x270 security/security.c:1302
search_binary_handler fs/exec.c:1660 [inline]
exec_binprm fs/exec.c:1702 [inline]
bprm_execve+0x8ee/0x1450 fs/exec.c:1754
do_execveat_common+0x510/0x6a0 fs/exec.c:1860
do_execve fs/exec.c:1934 [inline]
__do_sys_execve fs/exec.c:2010 [inline]
__se_sys_execve fs/exec.c:2005 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2005
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff888032f1ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888032f1cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888032f1cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888032f1cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888032f1cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.