================================================================== BUG: KASAN: use-after-free in dump_ipv6_mac_header net/netfilter/nf_log_syslog.c:891 [inline] BUG: KASAN: use-after-free in nf_log_ip6_packet+0x848/0x960 net/netfilter/nf_log_syslog.c:930 Read of size 1 at addr ffff888020c78fff by task kworker/1:18/7390 CPU: 1 PID: 7390 Comm: kworker/1:18 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Workqueue: mld mld_ifc_work Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 dump_ipv6_mac_header net/netfilter/nf_log_syslog.c:891 [inline] nf_log_ip6_packet+0x848/0x960 net/netfilter/nf_log_syslog.c:930 nf_log_packet+0x446/0x5f0 net/netfilter/nf_log.c:229 nft_log_eval+0x2c0/0x3b0 net/netfilter/nft_log.c:60 expr_call_ops_eval net/netfilter/nf_tables_core.c:198 [inline] nft_do_chain+0x491/0x14d0 net/netfilter/nf_tables_core.c:238 nft_do_chain_inet+0x25c/0x340 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584 nf_hook+0x205/0x360 include/linux/netfilter.h:257 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x273/0x3b0 net/ipv6/ip6_output.c:236 dst_output include/net/dst.h:452 [inline] NF_HOOK+0x165/0x460 include/linux/netfilter.h:302 mld_sendpack+0x6ee/0xc40 net/ipv6/mcast.c:1853 mld_send_cr net/ipv6/mcast.c:2152 [inline] mld_ifc_work+0x843/0xd60 net/ipv6/mcast.c:2688 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 4255: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x22c/0x750 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1162 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:664 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline] nsim_dev_trap_report_work+0x25c/0xab0 drivers/net/netdevsim/dev.c:762 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 4255: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 skb_free_head net/core/skbuff.c:655 [inline] skb_release_data+0x667/0x830 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb+0xa2/0x100 net/core/skbuff.c:918 nsim_dev_trap_report drivers/net/netdevsim/dev.c:737 [inline] nsim_dev_trap_report_work+0x771/0xab0 drivers/net/netdevsim/dev.c:762 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff888020c78000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 4095 bytes inside of 4096-byte region [ffff888020c78000, ffff888020c79000) The buggy address belongs to the page: page:ffffea0000831e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20c78 head:ffffea0000831e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888017842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 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 4194, ts 64447404253, free_ts 64428402656 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc_trace+0xf9/0x290 mm/slub.c:3250 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:359 [inline] ipv6_add_dev+0x5aa/0x11a0 net/ipv6/addrconf.c:409 addrconf_notify+0x66f/0xf20 net/ipv6/addrconf.c:3594 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] register_netdevice+0x12a8/0x1720 net/core/dev.c:10455 veth_newlink+0x6af/0xe20 drivers/net/veth.c:1687 __rtnl_newlink net/core/rtnetlink.c:3538 [inline] rtnl_newlink+0x139e/0x1920 net/core/rtnetlink.c:3586 rtnetlink_rcv_msg+0x7f1/0xf10 net/core/rtnetlink.c:5698 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2519 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x78f/0x940 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2073 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc_track_caller+0x187/0x330 mm/slub.c:4930 kvasprintf+0xe3/0x1a0 lib/kasprintf.c:25 kobject_set_name_vargs+0x5d/0x110 lib/kobject.c:297 kobject_add_varg lib/kobject.c:392 [inline] kobject_init_and_add+0xeb/0x190 lib/kobject.c:481 netdev_queue_add_kobject net/core/net-sysfs.c:1666 [inline] netdev_queue_update_kobjects+0x19c/0x3e0 net/core/net-sysfs.c:1711 register_queue_kobjects net/core/net-sysfs.c:1772 [inline] netdev_register_kobject+0x273/0x320 net/core/net-sysfs.c:2018 register_netdevice+0x10e8/0x1720 net/core/dev.c:10424 veth_newlink+0x6af/0xe20 drivers/net/veth.c:1687 Memory state around the buggy address: ffff888020c78e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020c78f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888020c78f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888020c79000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888020c79080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================