==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
BUG: KASAN: slab-use-after-free in gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112
Write of size 4 at addr ffff8880583f8b68 by task syz.5.1231/11400
CPU: 0 UID: 0 PID: 11400 Comm: syz.5.1231 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
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
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
handle_softirqs+0x22a/0x7c0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727
irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x330 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 01 bd ff 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 1b ad 76 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 40 9f 02 0a cc 48 8d 3d 38 cb 72
RSP: 0018:ffffc9000d7c79f8 EFLAGS: 00000282
RAX: 9fe3f72f37601c00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000e0136738 RSI: ffffffff8e1528a1 RDI: ffffffff8c275280
RBP: ffffffff826d158c R08: ffffffff826d158c R09: ffffffff8e7601a0
R10: dffffc0000000000 R11: ffffed1004e429e1 R12: 0000000000000002
R13: ffffffff8e7601a0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75
kernfs_next_descendant_post+0x4e/0x310 fs/kernfs/dir.c:1378
__kernfs_remove+0xfa/0x660 fs/kernfs/dir.c:1495
kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files fs/sysfs/group.c:28 [inline]
sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328
loop_sysfs_exit drivers/block/loop.c:739 [inline]
__loop_clr_fd drivers/block/loop.c:1145 [inline]
lo_release+0x416/0x840 drivers/block/loop.c:1773
bdev_release+0x536/0x650 block/bdev.c:-1
blkdev_release+0x15/0x20 block/fops.c:706
__fput+0x44f/0xa70 fs/file_table.c:469
fput_close_sync+0x11f/0x240 fs/file_table.c:574
__do_sys_close fs/open.c:1509 [inline]
__se_sys_close fs/open.c:1494 [inline]
__x64_sys_close+0x7e/0x110 fs/open.c:1494
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
RIP: 0033:0x7f2619f5b78e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f261ae4fdf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f261ae506c0 RCX: 00007f2619f5b78e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007f261ae4fea0 R14: 00000000000125c7 R15: 0000200000000180
Allocated by task 11400:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/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]
__kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5294
kmalloc_noprof include/linux/slab.h:962 [inline]
kzalloc_noprof include/linux/slab.h:1204 [inline]
init_sbd fs/gfs2/ops_fstype.c:79 [inline]
gfs2_fill_super+0x128/0x21d0 fs/gfs2/ops_fstype.c:1121
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3760 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3836
do_mount fs/namespace.c:4159 [inline]
__do_sys_mount fs/namespace.c:4348 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4325
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 11400:
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:2667 [inline]
slab_free mm/slub.c:6079 [inline]
kfree+0x1c1/0x610 mm/slub.c:6392
free_sbd fs/gfs2/ops_fstype.c:72 [inline]
gfs2_fill_super+0x150e/0x21d0 fs/gfs2/ops_fstype.c:1316
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3760 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3836
do_mount fs/namespace.c:4159 [inline]
__do_sys_mount fs/namespace.c:4348 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4325
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
The buggy address belongs to the object at ffff8880583f8000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2920 bytes inside of
freed 8192-byte region [ffff8880583f8000, ffff8880583fa000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x583f8
head: order:3 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 ffff88813ffa7280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ffa7280 dead000000000100 dead000000000122
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea000160fe01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7786, tgid 7784 (syz.6.385), ts 185747835768, free_ts 185740930936
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1883
prep_new_page mm/page_alloc.c:1891 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3956
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5244
alloc_slab_page mm/slub.c:3235 [inline]
allocate_slab+0x7b/0x660 mm/slub.c:3408
new_slab mm/slub.c:3466 [inline]
refill_objects+0x331/0x3c0 mm/slub.c:7084
refill_sheaf mm/slub.c:2784 [inline]
__pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4533
alloc_from_pcs mm/slub.c:4636 [inline]
slab_alloc_node mm/slub.c:4770 [inline]
__kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5289
kmalloc_noprof include/linux/slab.h:962 [inline]
kzalloc_noprof include/linux/slab.h:1204 [inline]
fat_fill_super+0x160/0x3530 fs/fat/inode.c:1557
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3760 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3836
do_mount fs/namespace.c:4159 [inline]
__do_sys_mount fs/namespace.c:4348 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4325
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
page last free pid 5196 tgid 5196 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1432 [inline]
__free_frozen_pages+0xc01/0xd80 mm/page_alloc.c:2972
__slab_free+0x263/0x2b0 mm/slub.c:5487
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4456 [inline]
slab_alloc_node mm/slub.c:4785 [inline]
kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4792
alloc_filename fs/namei.c:142 [inline]
do_getname+0x2e/0x250 fs/namei.c:182
getname include/linux/fs.h:2512 [inline]
class_filename_constructor include/linux/fs.h:2539 [inline]
do_sys_openat2+0xca/0x200 fs/open.c:1365
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
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:
ffff8880583f8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880583f8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880583f8b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880583f8b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880583f8c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 2 bytes skipped:
0: ff ljmp (bad)
1: e8 01 bd ff 09 call 0x9ffbd07
6: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp)
d: 00
e: 0f 84 3a ff ff ff je 0xffffff4e
14: 65 48 8b 05 1b ad 76 mov %gs:0x1176ad1b(%rip),%rax # 0x1176ad37
1b: 11
1c: 48 3b 44 24 58 cmp 0x58(%rsp),%rax
21: 75 33 jne 0x56
23: fb sti
24: 48 83 c4 60 add $0x60,%rsp
* 28: 5b pop %rbx <-- trapping instruction
29: 41 5c pop %r12
2b: 41 5d pop %r13
2d: 41 5e pop %r14
2f: 41 5f pop %r15
31: 5d pop %rbp
32: e9 40 9f 02 0a jmp 0xa029f77
37: cc int3
38: 48 rex.W
39: 8d .byte 0x8d
3a: 3d .byte 0x3d
3b: 38 cb cmp %cl,%bl
3d: 72 .byte 0x72