================================================================== 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+0x302/0x320 net/netfilter/core.c:319 Read of size 8 at addr ffff888021ffc108 by task kworker/u8:5/93 CPU: 1 UID: 0 PID: 93 Comm: kworker/u8:5 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: netns cleanup_net 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+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 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+0x302/0x320 net/netfilter/core.c:319 __nf_unregister_net_hook+0x7e/0x6a0 net/netfilter/core.c:491 nf_unregister_net_hook+0xda/0x120 net/netfilter/core.c:536 nft_unregister_flowtable_ops net/netfilter/nf_tables_api.c:8895 [inline] __nft_unregister_flowtable_net_hooks+0xf7/0x3f0 net/netfilter/nf_tables_api.c:8910 __nft_release_hook+0x243/0x360 net/netfilter/nf_tables_api.c:11899 __nft_release_hooks net/netfilter/nf_tables_api.c:11913 [inline] nf_tables_pre_exit_net+0xc5/0x120 net/netfilter/nf_tables_api.c:12064 ops_pre_exit_list net/core/net_namespace.c:161 [inline] ops_undo_list+0x187/0xab0 net/core/net_namespace.c:234 cleanup_net+0x499/0x920 net/core/net_namespace.c:704 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 93: 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] __do_kmalloc_node mm/slub.c:5219 [inline] __kmalloc_node_track_caller_noprof+0x304/0x850 mm/slub.c:5327 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635 __alloc_skb+0x185/0x710 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x2af/0xd10 drivers/net/netdevsim/dev.c:922 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 93: 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:2687 [inline] slab_free mm/slub.c:6124 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6442 skb_kfree_head net/core/skbuff.c:1089 [inline] skb_free_head+0x119/0x220 net/core/skbuff.c:1101 skb_release_data+0x79b/0x9d0 net/core/skbuff.c:1128 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb net/core/skbuff.c:1217 [inline] consume_skb net/core/skbuff.c:1450 [inline] consume_skb+0xc4/0x110 net/core/skbuff.c:1444 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline] nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:922 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888021ffc000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 264 bytes inside of freed 4096-byte region [ffff888021ffc000, ffff888021ffd000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21ff8 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 ffff88813fe3b140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe3b140 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000087fe01 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 93, tgid 93 (kworker/u8:5), ts 2097936431824, free_ts 2097688422043 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2484 alloc_slab_page mm/slub.c:3253 [inline] allocate_slab mm/slub.c:3444 [inline] new_slab+0x43a/0x6d0 mm/slub.c:3502 ___slab_alloc+0x2a0/0x850 mm/slub.c:4376 __slab_alloc_node mm/slub.c:4442 [inline] slab_alloc_node mm/slub.c:4818 [inline] __do_kmalloc_node mm/slub.c:5218 [inline] __kmalloc_node_track_caller_noprof+0x45c/0x850 mm/slub.c:5327 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635 __alloc_skb+0x185/0x710 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x2af/0xd10 drivers/net/netdevsim/dev.c:922 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 7414 tgid 7414 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 page_frag_free+0x284/0x2e0 mm/page_frag_cache.c:169 skb_free_frag include/linux/skbuff.h:3520 [inline] skb_free_head+0xa4/0x220 net/core/skbuff.c:1099 skb_release_data+0x79b/0x9d0 net/core/skbuff.c:1128 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb net/core/skbuff.c:1217 [inline] consume_skb net/core/skbuff.c:1450 [inline] consume_skb+0xc4/0x110 net/core/skbuff.c:1444 batadv_forw_packet_free+0x1c8/0x250 net/batman-adv/send.c:458 batadv_iv_send_outstanding_bat_ogm_packet+0x2c9/0x860 net/batman-adv/bat_iv_ogm.c:1715 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888021ffc000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021ffc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888021ffc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021ffc180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021ffc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================