===================================================== BUG: KMSAN: use-after-free in __write_once_size include/linux/compiler.h:233 [inline] BUG: KMSAN: use-after-free in __skb_unlink include/linux/skbuff.h:2025 [inline] BUG: KMSAN: use-after-free in __skb_dequeue include/linux/skbuff.h:2040 [inline] BUG: KMSAN: use-after-free in skb_dequeue net/core/skbuff.c:3040 [inline] BUG: KMSAN: use-after-free in skb_queue_purge+0x3b6/0x450 net/core/skbuff.c:3077 CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108 __msan_warning+0x64/0xc0 mm/kmsan/kmsan_instr.c:245 __write_once_size include/linux/compiler.h:233 [inline] __skb_unlink include/linux/skbuff.h:2025 [inline] __skb_dequeue include/linux/skbuff.h:2040 [inline] skb_dequeue net/core/skbuff.c:3040 [inline] skb_queue_purge+0x3b6/0x450 net/core/skbuff.c:3077 netlink_sock_destruct+0x17b/0x3d0 net/netlink/af_netlink.c:394 __sk_destruct+0x83/0x820 net/core/sock.c:1697 sk_destruct net/core/sock.c:1741 [inline] __sk_free+0x633/0x6e0 net/core/sock.c:1752 sk_free+0x6c/0x90 net/core/sock.c:1763 deferred_put_nlk_sk+0x2bb/0x340 net/netlink/af_netlink.c:729 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2157 [inline] rcu_core+0xc99/0x1b10 kernel/rcu/tree.c:2377 rcu_core_si+0xe/0x10 kernel/rcu/tree.c:2386 __do_softirq+0x4a1/0x83a kernel/softirq.c:293 run_ksoftirqd+0x25/0x40 kernel/softirq.c:607 smpboot_thread_fn+0x4a3/0x990 kernel/smpboot.c:165 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:149 [inline] kmsan_internal_poison_shadow+0x60/0x120 mm/kmsan/kmsan.c:132 kmsan_slab_free+0x7a/0xe0 mm/kmsan/kmsan_hooks.c:107 slab_free_freelist_hook mm/slub.c:1457 [inline] slab_free mm/slub.c:3020 [inline] kmem_cache_free+0x5ce/0x2c00 mm/slub.c:3036 kfree_skbmem net/core/skbuff.c:644 [inline] __kfree_skb+0x1dd/0x210 net/core/skbuff.c:680 consume_skb+0x2b0/0x2e0 net/core/skbuff.c:838 arp_process+0x2d13/0x4aa0 net/ipv4/arp.c:915 NF_HOOK include/linux/netfilter.h:305 [inline] arp_rcv+0x913/0x9f0 net/ipv4/arp.c:961 __netif_receive_skb_one_core net/core/dev.c:4929 [inline] __netif_receive_skb net/core/dev.c:5043 [inline] process_backlog+0x12a6/0x13c0 net/core/dev.c:5874 napi_poll net/core/dev.c:6311 [inline] net_rx_action+0x7a6/0x1aa0 net/core/dev.c:6379 __do_softirq+0x4a1/0x83a kernel/softirq.c:293 run_ksoftirqd+0x25/0x40 kernel/softirq.c:607 smpboot_thread_fn+0x4a3/0x990 kernel/smpboot.c:165 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353 =====================================================