===================================================== BUG: KMSAN: uninit-value in __netif_receive_skb_core+0x38f3/0x5870 net/core/dev.c:5111 CPU: 0 PID: 14893 Comm: syz-executor.1 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: 0033:0x45ca69 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:00007f510a0b8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000507a00 RCX: 000000000045ca69 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000018100 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000bae R14: 00000000004cea37 R15: 00007f510a0b96d4 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 =====================================================