==================================================================
BUG: KASAN: slab-use-after-free in llc_conn_ac_send_sabme_cmd_p_set_x+0x442/0x470 net/llc/llc_c_ac.c:782
Read of size 1 at addr ffff88802b6a6010 by task kworker/1:1H/1631
CPU: 1 UID: 0 PID: 1631 Comm: kworker/1:1H Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events_highpri snd_vmidi_output_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
llc_conn_ac_send_sabme_cmd_p_set_x+0x442/0x470 net/llc/llc_c_ac.c:782
llc_exec_conn_trans_actions net/llc/llc_conn.c:437 [inline]
llc_conn_service net/llc/llc_conn.c:362 [inline]
llc_conn_state_process+0x3ec/0x1480 net/llc/llc_conn.c:66
llc_process_tmr_ev net/llc/llc_c_ac.c:1442 [inline]
llc_conn_tmr_common_cb+0x2d4/0x880 net/llc/llc_c_ac.c:1325
call_timer_fn+0x19a/0x610 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers+0x757/0xb00 kernel/time/timer.c:2374
__run_timer_base kernel/time/timer.c:2386 [inline]
__run_timer_base kernel/time/timer.c:2378 [inline]
run_timer_base+0x114/0x190 kernel/time/timer.c:2395
run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2405
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 90 29 f6 48 89 df e8 1e e0 29 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 a5 ed 18 f6 65 8b 05 ee e6 a6 08 85 c0 74 16 5b
RSP: 0018:ffffc90005e17b38 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff888032805038 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffffff8e1a5870 RDI: ffffffff8c3ff580
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000293
R13: ffff888032805038 R14: 0000000000000001 R15: ffff888032897000
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
class_spinlock_irqsave_destructor include/linux/spinlock.h:619 [inline]
snd_rawmidi_transmit+0xf1/0x130 sound/core/rawmidi.c:1486
snd_vmidi_output_work+0x111/0x390 sound/core/seq/seq_virmidi.c:151
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 6121:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5489
_kmalloc_noprof include/linux/slab.h:988 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
llc_sap_alloc net/llc/llc_core.c:29 [inline]
llc_sap_open+0x120/0x3b0 net/llc/llc_core.c:96
llc_ui_autobind.isra.0+0x2ae/0x580 net/llc/af_llc.c:301
llc_ui_connect+0x582/0xdb0 net/llc/af_llc.c:498
__sys_connect_file+0x141/0x1a0 net/socket.c:2135
__sys_connect+0x141/0x170 net/socket.c:2154
__do_sys_connect net/socket.c:2160 [inline]
__se_sys_connect net/socket.c:2157 [inline]
__x64_sys_connect+0x72/0xb0 net/socket.c:2157
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 0:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2677 [inline]
__rcu_free_sheaf_prepare+0x5d/0x2f0 mm/slub.c:2928
rcu_free_sheaf+0x1a/0xe0 mm/slub.c:5978
rcu_do_batch kernel/rcu/tree.c:2645 [inline]
rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2897
handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
The buggy address belongs to the object at ffff88802b6a6000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 16 bytes inside of
freed 2048-byte region [ffff88802b6a6000, ffff88802b6a6800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802b6a2000 pfn:0x2b6a0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe24000 ffffea0000a5ec10 ffffea0001e01210
raw: ffff88802b6a2000 0000000800080005 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe24000 ffffea0000a5ec10 ffffea0001e01210
head: ffff88802b6a2000 0000000800080005 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 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 5610, tgid 5610 (syz-executor), ts 104181300719, free_ts 66201160868
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3266 [inline]
allocate_slab mm/slub.c:3380 [inline]
new_slab+0xa2/0x640 mm/slub.c:3426
refill_objects+0xe3/0x410 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
alloc_from_pcs mm/slub.c:4773 [inline]
slab_alloc_node mm/slub.c:4905 [inline]
__kmalloc_cache_noprof+0x479/0x6c0 mm/slub.c:5485
_kmalloc_noprof include/linux/slab.h:988 [inline]
rtnl_newlink+0x126/0x2380 net/core/rtnetlink.c:4059
rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7076
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
__sys_sendto+0x48b/0x4e0 net/socket.c:2252
__do_sys_sendto net/socket.c:2259 [inline]
__se_sys_sendto net/socket.c:2255 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2255
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5362 tgid 5362 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4584 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
__kmalloc_cache_noprof+0x265/0x6c0 mm/slub.c:5485
_kmalloc_noprof include/linux/slab.h:988 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
tomoyo_environ security/tomoyo/domain.c:634 [inline]
tomoyo_find_next_domain+0xc6e/0x2010 security/tomoyo/domain.c:889
tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline]
tomoyo_bprm_check_security+0x12d/0x1d0 security/tomoyo/tomoyo.c:92
security_bprm_check+0x87/0x1e0 security/security.c:820
search_binary_handler fs/exec.c:1684 [inline]
exec_binprm fs/exec.c:1726 [inline]
bprm_execve fs/exec.c:1778 [inline]
bprm_execve+0x84b/0x1730 fs/exec.c:1754
do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1876
__do_sys_execve fs/exec.c:1949 [inline]
__se_sys_execve fs/exec.c:1943 [inline]
__x64_sys_execve+0x93/0xd0 fs/exec.c:1943
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff88802b6a5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88802b6a5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802b6a6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802b6a6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802b6a6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
wlan0: beacon TX faster than countdown (channel/color switch) completion
----------------
Code disassembly (best guess):
0: f5 cmc
1: 53 push %rbx
2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi
7: 48 89 fb mov %rdi,%rbx
a: 48 83 c7 18 add $0x18,%rdi
e: e8 96 90 29 f6 call 0xf62990a9
13: 48 89 df mov %rbx,%rdi
16: e8 1e e0 29 f6 call 0xf629e039
1b: f7 c5 00 02 00 00 test $0x200,%ebp
21: 75 23 jne 0x46
23: 9c pushf
24: 58 pop %rax
25: f6 c4 02 test $0x2,%ah
28: 75 37 jne 0x61
* 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction
2f: e8 a5 ed 18 f6 call 0xf618edd9
34: 65 8b 05 ee e6 a6 08 mov %gs:0x8a6e6ee(%rip),%eax # 0x8a6e729
3b: 85 c0 test %eax,%eax
3d: 74 16 je 0x55
3f: 5b pop %rbx