================================================================== 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 ffff888035b72010 by task syz-executor/5603 CPU: 1 UID: 0 PID: 5603 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 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:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 bb 4b 7d 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 46 11 3c 0f 0f 82 ac 02 00 00 8b 35 0e 45 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 5d 4b 7d 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0000:ffffc90003557810 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e1810a7 RDI: ffffffff8c3ffa80 RBP: ffffffff8ebe8200 R08: 00000000ffffffff R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 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] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931 lsm_file_alloc security/security.c:171 [inline] security_file_alloc+0x34/0x2c0 security/security.c:2406 init_file+0x95/0x480 fs/file_table.c:184 alloc_empty_file+0x79/0x1c0 fs/file_table.c:266 alloc_file fs/file_table.c:396 [inline] alloc_file_pseudo+0x183/0x290 fs/file_table.c:427 sock_alloc_file+0x50/0x210 net/socket.c:532 sock_map_fd net/socket.c:562 [inline] __sys_socket+0x1c0/0x260 net/socket.c:1802 __do_sys_socket net/socket.c:1807 [inline] __se_sys_socket net/socket.c:1805 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1805 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 RIP: 0033:0x7f91e259f947 Code: f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 29 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe82e56bc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f91e259f947 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a RBP: 00007ffe82e572fc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f91e27ede00 R13: 00000000000927c0 R14: 000000000005b54b R15: 00007f91e27effc0 Allocated by task 8670: 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_bind+0xb67/0xe40 net/llc/af_llc.c:386 __sys_bind_socket net/socket.c:1920 [inline] __sys_bind_socket net/socket.c:1912 [inline] __sys_bind+0x1a9/0x260 net/socket.c:1951 __do_sys_bind net/socket.c:1956 [inline] __se_sys_bind net/socket.c:1954 [inline] __x64_sys_bind+0x72/0xb0 net/socket.c:1954 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 8574: 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 ffff888035b72000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 16 bytes inside of freed 2048-byte region [ffff888035b72000, ffff888035b72800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35b70 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 ffff88813fe22000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe22000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5598, tgid 5598 (syz-executor), ts 72899938584, free_ts 50235864302 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] _kzalloc_noprof include/linux/slab.h:1309 [inline] batadv_hardif_add_interface net/batman-adv/hard-interface.c:878 [inline] batadv_hard_if_event+0x14bf/0x3870 net/batman-adv/hard-interface.c:1087 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2250 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] register_netdevice+0x1998/0x25a0 net/core/dev.c:11484 veth_newlink+0x316/0xa00 drivers/net/veth.c:1863 rtnl_newlink_create net/core/rtnetlink.c:3913 [inline] __rtnl_newlink net/core/rtnetlink.c:4044 [inline] rtnl_newlink+0x1499/0x2380 net/core/rtnetlink.c:4159 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 page last free pid 5410 tgid 5410 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] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x2bf/0x820 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] tomoyo_add_entry security/tomoyo/common.c:2166 [inline] tomoyo_supervisor+0x65d/0x1340 security/tomoyo/common.c:2238 tomoyo_audit_path_log security/tomoyo/file.c:169 [inline] tomoyo_path_permission security/tomoyo/file.c:592 [inline] tomoyo_path_permission+0x270/0x3b0 security/tomoyo/file.c:577 tomoyo_path_perm+0x364/0x460 security/tomoyo/file.c:843 security_inode_getattr+0x116/0x280 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_fstat+0x4b/0xe0 fs/stat.c:281 __do_sys_newfstat+0x8b/0x110 fs/stat.c:551 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: ffff888035b71f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888035b71f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888035b72000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888035b72080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888035b72100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 05 bb 4b 7d 12 add $0x127d4bbb,%eax 5: 83 f8 07 cmp $0x7,%eax 8: 0f 87 da 00 00 00 ja 0xe8 e: 48 0f a3 05 46 11 3c bt %rax,0xf3c1146(%rip) # 0xf3c115c 15: 0f 16: 0f 82 ac 02 00 00 jb 0x2c8 1c: 8b 35 0e 45 3c 0f mov 0xf3c450e(%rip),%esi # 0xf3c4530 22: 85 f6 test %esi,%esi 24: 0f 85 c7 00 00 00 jne 0xf1 * 2a: 48 8b 44 24 30 mov 0x30(%rsp),%rax <-- trapping instruction 2f: 65 48 2b 05 5d 4b 7d sub %gs:0x127d4b5d(%rip),%rax # 0x127d4b94 36: 12 37: 0f 85 ec 02 00 00 jne 0x329 3d: 48 rex.W 3e: 83 .byte 0x83 3f: c4 .byte 0xc4