==================================================================
BUG: KASAN: slab-use-after-free in llc_conn_ac_send_sabme_cmd_p_set_x+0x38a/0x420 net/llc/llc_c_ac.c:782
Read of size 1 at addr ffff8880242fe010 by task kworker/1:0H/14375
CPU: 1 UID: 0 PID: 14375 Comm: kworker/1:0H Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Workqueue: events_highpri snd_vmidi_output_work
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
llc_conn_ac_send_sabme_cmd_p_set_x+0x38a/0x420 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+0x4fb/0x1380 net/llc/llc_conn.c:66
llc_process_tmr_ev net/llc/llc_c_ac.c:1442 [inline]
llc_conn_tmr_common_cb+0x34a/0x780 net/llc/llc_c_ac.c:1325
call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x226/0x860 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:finish_task_switch+0x413/0xc60 kernel/sched/core.c:5384
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 e9 db 06 00 00 49 83 c4 48 4c 89 e7 e8 47 3f 55 0a e8 72 2f 3a 00 fb 4c 8b 65 c8 <49> 8d bc 24 18 17 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc9000d9a76e0 EFLAGS: 00000206
RAX: 0000000001ca4b59 RBX: ffff8880b853c8e0 RCX: 8000000000000001
RDX: 0000000000000006 RSI: ffffffff8e469c7a RDI: ffffffff8c6ddc80
RBP: ffffc9000d9a7730 R08: ffffffff917a757f R09: 1ffffffff22f4eaf
R10: dffffc0000000000 R11: fffffbfff22f4eb0 R12: ffff888050491f40
R13: ffff8880b853c8a8 R14: dffffc0000000000 R15: 1ffff110170a791c
context_switch kernel/sched/core.c:5536 [inline]
__schedule+0x17e3/0x58f0 kernel/sched/core.c:7284
preempt_schedule_common+0x7f/0xd0 kernel/sched/core.c:7463
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
_raw_spin_unlock_irqrestore+0x76/0x80 kernel/locking/spinlock.c:221
spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
class_spinlock_irqsave_destructor include/linux/spinlock.h:644 [inline]
snd_rawmidi_transmit+0x9c/0xd0 sound/core/rawmidi.c:1496
snd_vmidi_output_work+0x1a5/0x3e0 sound/core/seq/seq_virmidi.c:152
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 24082:
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:409 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
llc_sap_alloc net/llc/llc_core.c:29 [inline]
llc_sap_open+0xe1/0x3b0 net/llc/llc_core.c:96
llc_ui_autobind+0x1f1/0x560 net/llc/af_llc.c:301
llc_ui_connect+0x1d7/0xd50 net/llc/af_llc.c:498
connect_socket net/socket.c:2141 [inline]
__sys_connect_file net/socket.c:2166 [inline]
__sys_connect+0x316/0x450 net/socket.c:2183
__do_sys_connect net/socket.c:2189 [inline]
__se_sys_connect net/socket.c:2186 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:2186
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 5879:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
__rcu_free_sheaf_prepare+0x12d/0x2a0 mm/slub.c:3009
rcu_free_sheaf+0x31/0x200 mm/slub.c:6061
rcu_do_batch kernel/rcu/tree.c:2650 [inline]
rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919
handle_softirqs+0x226/0x860 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 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 ffff8880242fe000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 16 bytes inside of
freed 2048-byte region [ffff8880242fe000, ffff8880242fe800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x242f8
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 ffff88801c042000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801c042000 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 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 1, tgid 1 (swapper/0), ts 3057582894
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
prep_new_page mm/page_alloc.c:1879 [inline]
get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
__alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
alloc_slab_page mm/slub.c:3347 [inline]
allocate_slab+0x7d/0x620 mm/slub.c:3462
new_slab mm/slub.c:3513 [inline]
refill_objects+0x2d5/0x350 mm/slub.c:7418
refill_sheaf mm/slub.c:2885 [inline]
__pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
__kmalloc_cache_noprof+0x39b/0x600 mm/slub.c:5559
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
acpi_ds_create_walk_state+0x96/0x270 drivers/acpi/acpica/dswstate.c:518
acpi_ps_execute_method+0x341/0xa70 drivers/acpi/acpica/psxface.c:134
acpi_ns_evaluate+0xd05/0x1320 drivers/acpi/acpica/nseval.c:205
acpi_evaluate_object+0x657/0xd70 drivers/acpi/acpica/nsxfeval.c:354
acpi_evaluate_integer+0x112/0x320 drivers/acpi/utils.c:260
acpi_bus_get_status_handle drivers/acpi/bus.c:82 [inline]
acpi_bus_get_status+0x150/0x3c0 drivers/acpi/bus.c:111
acpi_scan_init_status drivers/acpi/scan.c:1859 [inline]
acpi_add_single_object+0x3d3/0x1b60 drivers/acpi/scan.c:1892
acpi_bus_check_add+0x2b7/0x8a0 drivers/acpi/scan.c:2175
acpi_ns_walk_namespace+0x273/0x700 drivers/acpi/acpica/nswalk.c:-1
page_owner free stack trace missing
Memory state around the buggy address:
ffff8880242fdf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880242fdf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880242fe000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880242fe080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880242fe100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 00 00 add %al,(%rax)
2: 41 c7 84 24 20 0e 00 movl $0x0,0xe20(%r12)
9: 00 00 00 00 00
e: e9 db 06 00 00 jmp 0x6ee
13: 49 83 c4 48 add $0x48,%r12
17: 4c 89 e7 mov %r12,%rdi
1a: e8 47 3f 55 0a call 0xa553f66
1f: e8 72 2f 3a 00 call 0x3a2f96
24: fb sti
25: 4c 8b 65 c8 mov -0x38(%rbp),%r12
* 29: 49 8d bc 24 18 17 00 lea 0x1718(%r12),%rdi <-- trapping instruction
30: 00
31: 48 89 f8 mov %rdi,%rax
34: 48 c1 e8 03 shr $0x3,%rax
38: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax
3d: 84 c0 test %al,%al