===================================================== BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] BUG: KMSAN: uninit-value in IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] BUG: KMSAN: uninit-value in ip_tunnel_rcv+0xf3f/0x2fa0 net/ipv4/ip_tunnel.c:395 __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] ip_tunnel_rcv+0xf3f/0x2fa0 net/ipv4/ip_tunnel.c:395 __ipgre_rcv+0x976/0xb60 net/ipv4/ip_gre.c:389 ipgre_rcv net/ipv4/ip_gre.c:411 [inline] gre_rcv+0x424/0x1a30 net/ipv4/ip_gre.c:447 gre_rcv+0x1e9/0x390 net/ipv4/gre_demux.c:163 ip_protocol_deliver_rcu+0x201/0xaf0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2a5/0x3a0 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:302 [inline] ip_local_deliver+0x278/0x4a0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:455 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip_rcv+0x527/0x7c0 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x1b3/0x5d0 net/core/dev.c:5603 netif_receive_skb_internal+0x53/0x340 net/core/dev.c:5689 netif_receive_skb+0x35/0x350 net/core/dev.c:5748 tun_rx_batched+0x837/0x930 tun_get_user+0x3bc6/0x4300 drivers/net/tun.c:2006 tun_chr_write_iter+0x3ab/0x5d0 drivers/net/tun.c:2036 call_write_iter include/linux/fs.h:2199 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x830/0x1570 fs/read_write.c:584 ksys_write+0x21b/0x4e0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x8f/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: __alloc_pages+0x9f1/0xe80 mm/page_alloc.c:5581 alloc_pages+0xaae/0xd80 mm/mempolicy.c:2285 skb_page_frag_refill+0x128/0x7b0 net/core/sock.c:2843 tun_build_skb+0x170/0x1890 drivers/net/tun.c:1671 tun_get_user+0xd9d/0x4300 drivers/net/tun.c:1811 tun_chr_write_iter+0x3ab/0x5d0 drivers/net/tun.c:2036 call_write_iter include/linux/fs.h:2199 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x830/0x1570 fs/read_write.c:584 ksys_write+0x21b/0x4e0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x8f/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd CPU: 0 PID: 3981 Comm: syz-executor.0 Not tainted 6.1.0-syzkaller-00014-g5c6259d6d19f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 =====================================================