==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [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+0x7a/0xf0 fs/gfs2/quota.c:112
Write of size 4 at addr ffff888031350b18 by task syz.6.562/8231
CPU: 1 UID: 0 PID: 8231 Comm: syz.6.562 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:194 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
gfs2_qd_dealloc+0x7a/0xf0 fs/gfs2/quota.c:112
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0x79c/0x1530 kernel/rcu/tree.c:2861
handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: d6 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 85 e9 0e 0f 82 74 02 00 00 8b 35 7a b5 e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 d6 08 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc900042bfc18 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffff88802524cd20 RCX: ffffffff93a93f60
RDX: 0000000000000000 RSI: ffffffff8da05443 RDI: ffffffff8bf079c0
RBP: 0000000000000001 R08: 14128129e3c1c85b R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
__might_fault mm/memory.c:7099 [inline]
__might_fault+0x113/0x190 mm/memory.c:7093
do_recvmmsg+0x327/0x750 net/socket.c:2993
__sys_recvmmsg net/socket.c:3061 [inline]
__do_sys_recvmmsg net/socket.c:3084 [inline]
__se_sys_recvmmsg net/socket.c:3077 [inline]
__x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3077
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fddc278f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fddc3651038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fddc29e6090 RCX: 00007fddc278f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fddc2813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fddc29e6128 R14: 00007fddc29e6090 R15: 00007ffff8570318
Allocated by task 8202:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
init_sbd fs/gfs2/ops_fstype.c:78 [inline]
gfs2_fill_super+0x140/0x2d30 fs/gfs2/ops_fstype.c:1128
get_tree_bdev_flags+0x38c/0x620 fs/super.c:1698
gfs2_get_tree+0x4e/0x280 fs/gfs2/ops_fstype.c:1337
vfs_get_tree+0x8e/0x340 fs/super.c:1758
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3642 [inline]
do_new_mount fs/namespace.c:3718 [inline]
path_mount+0x7b9/0x23a0 fs/namespace.c:4028
do_mount fs/namespace.c:4041 [inline]
__do_sys_mount fs/namespace.c:4229 [inline]
__se_sys_mount fs/namespace.c:4206 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4206
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 8202:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2543 [inline]
slab_free mm/slub.c:6642 [inline]
kfree+0x2b8/0x6d0 mm/slub.c:6849
free_sbd fs/gfs2/ops_fstype.c:71 [inline]
gfs2_fill_super+0x1553/0x2d30 fs/gfs2/ops_fstype.c:1321
get_tree_bdev_flags+0x38c/0x620 fs/super.c:1698
gfs2_get_tree+0x4e/0x280 fs/gfs2/ops_fstype.c:1337
vfs_get_tree+0x8e/0x340 fs/super.c:1758
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3642 [inline]
do_new_mount fs/namespace.c:3718 [inline]
path_mount+0x7b9/0x23a0 fs/namespace.c:4028
do_mount fs/namespace.c:4041 [inline]
__do_sys_mount fs/namespace.c:4229 [inline]
__se_sys_mount fs/namespace.c:4206 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4206
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888031350000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2840 bytes inside of
freed 8192-byte region [ffff888031350000, ffff888031352000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31350
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 ffffea0000c4d401 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 7407, tgid 7405 (syz.4.355), ts 294471288894, free_ts 294425799614
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1845
prep_new_page mm/page_alloc.c:1853 [inline]
get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3879
__alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5178
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:3059 [inline]
allocate_slab mm/slub.c:3232 [inline]
new_slab+0x24a/0x360 mm/slub.c:3286
___slab_alloc+0xd79/0x1a50 mm/slub.c:4655
__slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4778
__slab_alloc_node mm/slub.c:4854 [inline]
slab_alloc_node mm/slub.c:5276 [inline]
__do_kmalloc_node mm/slub.c:5649 [inline]
__kmalloc_noprof+0x501/0x880 mm/slub.c:5662
kmalloc_noprof include/linux/slab.h:961 [inline]
sock_kmalloc+0x111/0x170 net/core/sock.c:2850
____sys_sendmsg+0x52a/0xc70 net/socket.c:2602
___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
__sys_sendmsg+0x16d/0x220 net/socket.c:2716
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 7408 tgid 7408 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2901
discard_slab mm/slub.c:3330 [inline]
__put_partials+0x130/0x170 mm/slub.c:3876
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4978 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
kmem_cache_alloc_lru_noprof+0x254/0x6e0 mm/slub.c:5307
__d_alloc+0x32/0xae0 fs/dcache.c:1690
d_alloc+0x4a/0x1e0 fs/dcache.c:1769
lookup_one_qstr_excl+0x175/0x250 fs/namei.c:1701
filename_create+0x1e7/0x4a0 fs/namei.c:4227
do_symlinkat+0xbe/0x310 fs/namei.c:4836
__do_sys_symlinkat fs/namei.c:4859 [inline]
__se_sys_symlinkat fs/namei.c:4856 [inline]
__x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4856
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff888031350a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888031350a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888031350b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888031350b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888031350c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 08 12 or %dl,(%rdx)
2: 83 f8 07 cmp $0x7,%eax
5: 0f 87 bc 02 00 00 ja 0x2c7
b: 89 c0 mov %eax,%eax
d: 48 0f a3 05 22 85 e9 bt %rax,0xee98522(%rip) # 0xee98537
14: 0e
15: 0f 82 74 02 00 00 jb 0x28f
1b: 8b 35 7a b5 e9 0e mov 0xee9b57a(%rip),%esi # 0xee9b59b
21: 85 f6 test %esi,%esi
23: 0f 85 8d 00 00 00 jne 0xb6
* 29: 48 8b 44 24 30 mov 0x30(%rsp),%rax <-- trapping instruction
2e: 65 48 2b 05 39 d6 08 sub %gs:0x1208d639(%rip),%rax # 0x1208d66f
35: 12
36: 0f 85 c7 02 00 00 jne 0x303
3c: 48 rex.W
3d: 83 .byte 0x83
3e: c4 .byte 0xc4