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BUG: KMSAN: uninit-value in deliver_ptype_list_skb net/core/dev.c:5240 [inline]
BUG: KMSAN: uninit-value in __netif_receive_skb_core+0x50f8/0x5890 net/core/dev.c:5232
CPU: 0 PID: 27408 Comm: syz-executor.5 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1df/0x240 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 deliver_ptype_list_skb net/core/dev.c:5240 [inline]
 __netif_receive_skb_core+0x50f8/0x5890 net/core/dev.c:5232
 __netif_receive_skb_list_core+0x34b/0x14d0 net/core/dev.c:5357
 __netif_receive_skb_list net/core/dev.c:5424 [inline]
 netif_receive_skb_list_internal+0xf66/0x1610 net/core/dev.c:5531
 gro_normal_list net/core/dev.c:5642 [inline]
 napi_complete_done+0x439/0xe10 net/core/dev.c:6367
 gro_cell_poll+0x3a9/0x400 net/core/gro_cells.c:65
 napi_poll net/core/dev.c:6684 [inline]
 net_rx_action+0x746/0x1aa0 net/core/dev.c:6752
 __do_softirq+0x311/0x83d kernel/softirq.c:293
 asm_call_on_stack+0x12/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:23 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline]
 do_softirq_own_stack+0x7c/0xa0 arch/x86/kernel/irq_64.c:77
 do_softirq kernel/softirq.c:338 [inline]
 __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:190
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 tun_rx_batched include/linux/skbuff.h:4327 [inline]
 tun_get_user+0x6dfd/0x72f0 drivers/net/tun.c:1972
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:2001
 call_write_iter include/linux/fs.h:1908 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xd98/0x1480 fs/read_write.c:578
 ksys_write+0x267/0x450 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:640
 __x64_sys_write+0x4a/0x70 fs/read_write.c:640
 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1d9
Code: Bad RIP value.
RSP: 002b:00007fae39ed7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000037740 RCX: 000000000045c1d9
RDX: 0000000000000fcc RSI: 0000000020000180 RDI: 0000000000000003
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 0000000000c9fb6f R14: 00007fae39ed89c0 R15: 000000000078bf0c

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165
 vlan_set_encap_proto include/linux/if_vlan.h:656 [inline]
 skb_vlan_untag+0x9a2/0xdb0 net/core/skbuff.c:5431
 __netif_receive_skb_core+0x72d/0x5890 net/core/dev.c:5119
 __netif_receive_skb_list_core+0x34b/0x14d0 net/core/dev.c:5357
 __netif_receive_skb_list net/core/dev.c:5424 [inline]
 netif_receive_skb_list_internal+0xf66/0x1610 net/core/dev.c:5531
 gro_normal_list net/core/dev.c:5642 [inline]
 napi_complete_done+0x439/0xe10 net/core/dev.c:6367
 gro_cell_poll+0x3a9/0x400 net/core/gro_cells.c:65
 napi_poll net/core/dev.c:6684 [inline]
 net_rx_action+0x746/0x1aa0 net/core/dev.c:6752
 __do_softirq+0x311/0x83d kernel/softirq.c:293

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2839 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4478
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1083 [inline]
 alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5770
 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2356
 tun_alloc_skb drivers/net/tun.c:1494 [inline]
 tun_get_user+0x10b7/0x72f0 drivers/net/tun.c:1811
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:2001
 call_write_iter include/linux/fs.h:1908 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xd98/0x1480 fs/read_write.c:578
 ksys_write+0x267/0x450 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:640
 __x64_sys_write+0x4a/0x70 fs/read_write.c:640
 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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