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BUG: KMSAN: uninit-value in __netif_receive_skb_core+0x38f3/0x5870 net/core/dev.c:5111
CPU: 0 PID: 32203 Comm: syz-executor.0 Not tainted 5.7.0-rc4-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+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 __netif_receive_skb_core+0x38f3/0x5870 net/core/dev.c:5111
 __netif_receive_skb_one_core net/core/dev.c:5186 [inline]
 __netif_receive_skb net/core/dev.c:5302 [inline]
 netif_receive_skb_internal net/core/dev.c:5392 [inline]
 netif_receive_skb+0x551/0xf20 net/core/dev.c:5451
 tun_rx_batched drivers/net/tun.c:1516 [inline]
 tun_get_user+0x6d60/0x71e0 drivers/net/tun.c:1963
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:497
 __kernel_write+0x205/0x600 fs/read_write.c:516
 write_pipe_buf+0x1f9/0x2a0 fs/splice.c:809
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x539/0xed0 fs/splice.c:636
 splice_from_pipe fs/splice.c:671 [inline]
 default_file_splice_write+0x1ee/0x3c0 fs/splice.c:821
 do_splice_from fs/splice.c:863 [inline]
 do_splice+0x1eae/0x2ec0 fs/splice.c:1170
 __do_sys_splice fs/splice.c:1447 [inline]
 __se_sys_splice+0x426/0x520 fs/splice.c:1427
 __x64_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ca59
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7e42427c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00000000005086e0 RCX: 000000000045ca59
RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 000000000078bfa0 R08: 0000000000018100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000bd1 R14: 00000000004cece6 R15: 00007f7e424286d4

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:641 [inline]
 skb_vlan_untag+0x9a2/0xdb0 net/core/skbuff.c:5433
 __netif_receive_skb_core+0x700/0x5870 net/core/dev.c:5033
 __netif_receive_skb_one_core net/core/dev.c:5186 [inline]
 __netif_receive_skb net/core/dev.c:5302 [inline]
 netif_receive_skb_internal net/core/dev.c:5392 [inline]
 netif_receive_skb+0x551/0xf20 net/core/dev.c:5451
 tun_rx_batched drivers/net/tun.c:1516 [inline]
 tun_get_user+0x6d60/0x71e0 drivers/net/tun.c:1963
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:497
 __kernel_write+0x205/0x600 fs/read_write.c:516
 write_pipe_buf+0x1f9/0x2a0 fs/splice.c:809
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x539/0xed0 fs/splice.c:636
 splice_from_pipe fs/splice.c:671 [inline]
 default_file_splice_write+0x1ee/0x3c0 fs/splice.c:821
 do_splice_from fs/splice.c:863 [inline]
 do_splice+0x1eae/0x2ec0 fs/splice.c:1170
 __do_sys_splice fs/splice.c:1447 [inline]
 __se_sys_splice+0x426/0x520 fs/splice.c:1427
 __x64_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

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:2802 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4436
 __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:5772
 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2265
 tun_alloc_skb drivers/net/tun.c:1492 [inline]
 tun_get_user+0x1260/0x71e0 drivers/net/tun.c:1808
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:497
 __kernel_write+0x205/0x600 fs/read_write.c:516
 write_pipe_buf+0x1f9/0x2a0 fs/splice.c:809
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x539/0xed0 fs/splice.c:636
 splice_from_pipe fs/splice.c:671 [inline]
 default_file_splice_write+0x1ee/0x3c0 fs/splice.c:821
 do_splice_from fs/splice.c:863 [inline]
 do_splice+0x1eae/0x2ec0 fs/splice.c:1170
 __do_sys_splice fs/splice.c:1447 [inline]
 __se_sys_splice+0x426/0x520 fs/splice.c:1427
 __x64_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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