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BUG: KMSAN: uninit-value in __netif_receive_skb_core+0x38f3/0x5870 net/core/dev.c:5111
CPU: 0 PID: 21457 Comm: syz-executor.5 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
 __ia32_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f8ddd9
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d670cc EFLAGS: 00000296 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000018100
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

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
 __ia32_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139

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
 __ia32_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
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