================================================================== BUG: KASAN: slab-use-after-free in read_pnet include/net/net_namespace.h:419 [inline] BUG: KASAN: slab-use-after-free in dev_net include/linux/netdevice.h:2741 [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 ffff8880353c8108 by task kworker/u8:4/16079 CPU: 0 UID: 0 PID: 16079 Comm: kworker/u8:4 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 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+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 read_pnet include/net/net_namespace.h:419 [inline] dev_net include/linux/netdevice.h:2741 [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:8905 [inline] __nft_unregister_flowtable_net_hooks net/netfilter/nf_tables_api.c:8920 [inline] __nft_release_hook net/netfilter/nf_tables_api.c:11904 [inline] __nft_release_hooks net/netfilter/nf_tables_api.c:11918 [inline] nf_tables_pre_exit_net+0x64a/0x900 net/netfilter/nf_tables_api.c:12069 ops_pre_exit_list net/core/net_namespace.c:161 [inline] ops_undo_list+0x187/0x940 net/core/net_namespace.c:234 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5809: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4921 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713 alloc_skb_fclone include/linux/skbuff.h:1433 [inline] tcp_stream_alloc_skb+0x3f/0x580 net/ipv4/tcp.c:945 tcp_sendmsg_locked+0x1375/0x5490 net/ipv4/tcp.c:1270 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1465 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_write_iter+0x406/0x4f0 net/socket.c:1195 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 5809: 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:2692 [inline] slab_free mm/slub.c:6168 [inline] kmem_cache_free+0x187/0x630 mm/slub.c:6298 skb_kfree_head net/core/skbuff.c:1087 [inline] skb_free_head net/core/skbuff.c:1101 [inline] skb_release_data+0x6c3/0x940 net/core/skbuff.c:1128 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1217 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3698 [inline] tcp_ack+0x2826/0x7da0 net/ipv4/tcp_input.c:4366 tcp_rcv_established+0x1478/0x2740 net/ipv4/tcp_input.c:6608 tcp_v4_do_rcv+0xa90/0x1430 net/ipv4/tcp_ipv4.c:1884 sk_backlog_rcv include/net/sock.h:1185 [inline] __release_sock+0x265/0x3a0 net/core/sock.c:3213 release_sock+0x5f/0x1f0 net/core/sock.c:3795 tcp_sendmsg+0x39/0x50 net/ipv4/tcp.c:1466 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] sock_write_iter+0x406/0x4f0 net/socket.c:1195 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff8880353c8000 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 264 bytes inside of freed 704-byte region [ffff8880353c8000, ffff8880353c82c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x353c8 head: order:2 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 ffff888140ec0b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800130013 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff888140ec0b40 dead000000000100 dead000000000122 head: 0000000000000000 0000000800130013 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000d4f201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 0, tgid 0 (swapper/1), ts 718290442195, free_ts 687052733153 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:3296 [inline] allocate_slab+0x77/0x660 mm/slub.c:3485 new_slab mm/slub.c:3543 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7178 __pcs_replace_empty_main+0x2f9/0x5e0 mm/slub.c:-1 alloc_from_pcs mm/slub.c:4720 [inline] slab_alloc_node mm/slub.c:4854 [inline] kmem_cache_alloc_node_noprof+0x441/0x690 mm/slub.c:4921 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x27d/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] ndisc_alloc_skb+0x9f/0x480 net/ipv6/ndisc.c:420 ndisc_send_rs+0x2b5/0x630 net/ipv6/ndisc.c:706 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4041 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 kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 page last free pid 16553 tgid 16553 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:5576 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:4542 [inline] slab_alloc_node mm/slub.c:4869 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4876 alloc_filename fs/namei.c:142 [inline] do_getname+0x2e/0x250 fs/namei.c:182 getname include/linux/fs.h:2512 [inline] class_filename_constructor include/linux/fs.h:2539 [inline] __do_sys_chdir fs/open.c:557 [inline] __se_sys_chdir+0x8d/0x2a0 fs/open.c:552 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Memory state around the buggy address: ffff8880353c8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880353c8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880353c8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880353c8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880353c8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================