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BUG: KASAN: slab-out-of-bounds in lec_arp_clear_vccs+0x6c/0x380 net/atm/lec.c:1260
Read of size 8 at addr ffff8880883d96d0 by task syz.4.15098/28630

CPU: 0 UID: 0 PID: 28630 Comm: syz.4.15098 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 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
 lec_arp_clear_vccs+0x6c/0x380 net/atm/lec.c:1260
 lec_arp_expire_vcc+0x17d/0x370 net/atm/lec.c:1598
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 bpf_test_run+0x3a8/0x830 net/bpf/test_run.c:426
 bpf_prog_test_run_skb+0xd22/0x1c90 net/bpf/test_run.c:1159
 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4722
 __sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6246
 __do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fccfd19c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fccfe0fb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fccfd415fa0 RCX: 00007fccfd19c799
RDX: 0000000000000050 RSI: 00002000000002c0 RDI: 000000000000000a
RBP: 00007fccfd232bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fccfd416038 R14: 00007fccfd415fa0 R15: 00007ffeab49c798
 </TASK>

Allocated by task 16073:
 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]
 __do_kmalloc_node mm/slub.c:5219 [inline]
 __kmalloc_noprof+0x35c/0x760 mm/slub.c:5231
 kmalloc_noprof include/linux/slab.h:966 [inline]
 kzalloc_noprof include/linux/slab.h:1200 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379
 neigh_sysctl_register+0x9b1/0xa90 net/core/neighbour.c:3922
 devinet_sysctl_register+0xad/0x200 net/ipv4/devinet.c:2714
 inetdev_init+0x2a4/0x4e0 net/ipv4/devinet.c:291
 inetdev_event+0x30d/0x1610 net/ipv4/devinet.c:1590
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x173a/0x1cf0 net/core/dev.c:11474
 veth_newlink+0x4a4/0xb70 drivers/net/veth.c:1860
 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3840
 __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
 rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 __sys_sendto+0x709/0x7a0 net/socket.c:2205
 __do_sys_sendto net/socket.c:2212 [inline]
 __se_sys_sendto net/socket.c:2208 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2208
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880883d9000
 which belongs to the cache kmalloc-cg-1k of size 1024
The buggy address is located 1112 bytes to the right of
 allocated 632-byte region [ffff8880883d9000, ffff8880883d9278)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x883d8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880883d8411
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813febf280 dead000000000100 dead000000000122
raw: 0000000000000000 0000080000100010 00000000f5000000 ffff8880883d8411
head: 00fff00000000040 ffff88813febf280 dead000000000100 dead000000000122
head: 0000000000000000 0000080000100010 00000000f5000000 ffff8880883d8411
head: 00fff00000000003 ffffea000220f601 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 27890, tgid 27890 (syz-executor), ts 599526768039, free_ts 599443559886
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3255 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3444
 new_slab mm/slub.c:3502 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7134
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4578
 alloc_from_pcs mm/slub.c:4681 [inline]
 slab_alloc_node mm/slub.c:4815 [inline]
 __do_kmalloc_node mm/slub.c:5218 [inline]
 __kmalloc_noprof+0x474/0x760 mm/slub.c:5231
 kmalloc_noprof include/linux/slab.h:966 [inline]
 kzalloc_noprof include/linux/slab.h:1200 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379
 neigh_sysctl_register+0x9b1/0xa90 net/core/neighbour.c:3922
 devinet_sysctl_register+0xad/0x200 net/ipv4/devinet.c:2714
 inetdev_init+0x2a4/0x4e0 net/ipv4/devinet.c:291
 inetdev_event+0x30d/0x1610 net/ipv4/devinet.c:1590
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x173a/0x1cf0 net/core/dev.c:11474
 register_vlan_dev+0x388/0x800 net/8021q/vlan.c:179
 vlan_newlink+0x4b2/0x610 net/8021q/vlan_netlink.c:194
page last free pid 27890 tgid 27890 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
 __slab_free+0x263/0x2b0 mm/slub.c:5532
 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:4501 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 __kmalloc_cache_noprof+0x2ba/0x660 mm/slub.c:5334
 kmalloc_noprof include/linux/slab.h:962 [inline]
 __netdev_adjacent_dev_insert+0x15b/0x980 net/core/dev.c:8721
 __netdev_adjacent_dev_link_lists net/core/dev.c:8813 [inline]
 __netdev_adjacent_dev_link_neighbour net/core/dev.c:8842 [inline]
 __netdev_upper_dev_link+0xa19/0xc80 net/core/dev.c:8902
 netdev_master_upper_dev_link+0xbc/0x110 net/core/dev.c:8977
 hsr_portdev_setup net/hsr/hsr_slave.c:165 [inline]
 hsr_add_port+0x678/0xa30 net/hsr/hsr_slave.c:213
 hsr_dev_finalize+0x6c4/0xaa0 net/hsr/hsr_device.c:792
 hsr_newlink+0x7ea/0x970 net/hsr/hsr_netlink.c:128
 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3840
 __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
 rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550

Memory state around the buggy address:
 ffff8880883d9580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880883d9600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880883d9680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff8880883d9700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880883d9780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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