================================================================== BUG: KASAN: slab-use-after-free in read_pnet include/net/net_namespace.h:414 [inline] BUG: KASAN: slab-use-after-free in dev_net include/linux/netdevice.h:2738 [inline] BUG: KASAN: slab-use-after-free in nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319 Read of size 8 at addr ffff88805a764108 by task kworker/u8:13/6003 CPU: 1 UID: 0 PID: 6003 Comm: kworker/u8:13 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 read_pnet include/net/net_namespace.h:414 [inline] dev_net include/linux/netdevice.h:2738 [inline] nf_hook_entry_head+0x1f1/0x2c0 net/netfilter/core.c:319 __nf_unregister_net_hook+0x74/0x6f0 net/netfilter/core.c:491 nft_unregister_flowtable_ops net/netfilter/nf_tables_api.c:9038 [inline] __nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:9053 [inline] __nft_release_hook+0x180/0x350 net/netfilter/nf_tables_api.c:12035 __nft_release_hooks net/netfilter/nf_tables_api.c:12049 [inline] nf_tables_pre_exit_net+0xa7/0x110 net/netfilter/nf_tables_api.c:12200 ops_pre_exit_list net/core/net_namespace.c:161 [inline] ops_undo_list+0x187/0x990 net/core/net_namespace.c:234 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 9825: 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] __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline] ipv6_add_dev+0x6aa/0x13a0 net/ipv6/addrconf.c:413 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3650 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] register_netdevice+0x15bd/0x1a70 net/core/dev.c:11431 ip6gre_newlink_common+0x3dd/0x590 net/ipv6/ip6_gre.c:1965 ip6gre_newlink+0x228/0x360 net/ipv6/ip6_gre.c:1998 rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1c0/0x660 mm/slub.c:6878 snmp6_free_dev net/ipv6/addrconf_core.c:247 [inline] in6_dev_finish_destroy_rcu+0x3b/0xa0 net/ipv6/addrconf_core.c:256 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xc8e/0x1720 kernel/rcu/tree.c:2857 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88805a764000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 264 bytes inside of freed 4096-byte region [ffff88805a764000, ffff88805a765000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a760 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88805a318801 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffb0500 ffffea0000cfe200 dead000000000002 raw: 0000000000000000 0000000000040004 00000000f5000000 ffff88805a318801 head: 00fff00000000040 ffff88813ffb0500 ffffea0000cfe200 dead000000000002 head: 0000000000000000 0000000000040004 00000000f5000000 ffff88805a318801 head: 00fff00000000003 ffffea000169d801 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 9040, tgid 9038 (syz.2.734), ts 189201818880, free_ts 188808042323 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857 prep_new_page mm/page_alloc.c:1865 [inline] get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xe53/0x1820 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x47d/0x800 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379 __addrconf_sysctl_register+0x328/0x4c0 net/ipv6/addrconf.c:7323 addrconf_init_net+0x4f9/0x790 net/ipv6/addrconf.c:7447 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0x110/0x330 net/core/net_namespace.c:446 copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:226 page last free pid 9031 tgid 9030 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x146/0x170 mm/slub.c:3886 __slab_free+0x294/0x320 mm/slub.c:5952 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:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x3cf/0x800 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723 security_file_ioctl+0xcb/0x2d0 security/security.c:2435 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805a764000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a764080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a764100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a764180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a764200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================