===================================================== BUG: KMSAN: uninit-value in ____bpf_skb_load_helper_32 net/core/filter.c:238 [inline] BUG: KMSAN: uninit-value in bpf_skb_load_helper_32+0xee/0x2d0 net/core/filter.c:232 CPU: 1 PID: 13839 Comm: syz-executor.4 Not tainted 5.8.0-rc5-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+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 ____bpf_skb_load_helper_32 net/core/filter.c:238 [inline] bpf_skb_load_helper_32+0xee/0x2d0 net/core/filter.c:232 ___bpf_prog_run+0x214d/0x97a0 kernel/bpf/core.c:1516 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:597 [inline] bpf_prog_run_clear_cb include/linux/filter.h:719 [inline] run_filter net/packet/af_packet.c:2012 [inline] packet_rcv+0x70f/0x2150 net/packet/af_packet.c:2085 deliver_skb net/core/dev.c:2247 [inline] __netif_receive_skb_core+0xe19/0x5890 net/core/dev.c:5132 __netif_receive_skb_one_core net/core/dev.c:5279 [inline] __netif_receive_skb net/core/dev.c:5395 [inline] process_backlog+0x605/0x14e0 net/core/dev.c:6239 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 __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 rcu_read_unlock_bh include/linux/rcupdate.h:723 [inline] ip_finish_output2+0x1fee/0x24a0 net/ipv4/ip_output.c:229 __ip_finish_output+0xaa7/0xd80 net/ipv4/ip_output.c:306 ip_finish_output+0x166/0x410 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_mc_output+0xfbf/0x1090 net/ipv4/ip_output.c:415 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:125 [inline] ip_send_skb+0x179/0x360 net/ipv4/ip_output.c:1560 udp_send_skb+0x1046/0x18b0 net/ipv4/udp.c:894 udp_sendmsg+0x3bb5/0x4100 net/ipv4/udp.c:1181 inet_sendmsg+0x276/0x2e0 net/ipv4/af_inet.c:814 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x10e2/0x1400 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmmsg+0x60e/0xd80 net/socket.c:2496 __do_sys_sendmmsg net/socket.c:2525 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2522 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2522 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:00007f403a906c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000025a40 RCX: 000000000045c1d9 RDX: 04000000000001a8 RSI: 0000000020007fc0 RDI: 0000000000000004 RBP: 000000000078c1c8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c18c R13: 0000000000c9fb6f R14: 00007f403a9079c0 R15: 000000000078c18c 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 ___bpf_prog_run+0x6cbe/0x97a0 kernel/bpf/core.c:1391 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:597 [inline] bpf_prog_run_clear_cb include/linux/filter.h:719 [inline] run_filter net/packet/af_packet.c:2012 [inline] packet_rcv+0x70f/0x2150 net/packet/af_packet.c:2085 deliver_skb net/core/dev.c:2247 [inline] __netif_receive_skb_core+0xe19/0x5890 net/core/dev.c:5132 __netif_receive_skb_one_core net/core/dev.c:5279 [inline] __netif_receive_skb net/core/dev.c:5395 [inline] process_backlog+0x605/0x14e0 net/core/dev.c:6239 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 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 ___bpf_prog_run+0x6c64/0x97a0 kernel/bpf/core.c:1391 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:597 [inline] bpf_prog_run_clear_cb include/linux/filter.h:719 [inline] run_filter net/packet/af_packet.c:2012 [inline] packet_rcv+0x70f/0x2150 net/packet/af_packet.c:2085 deliver_skb net/core/dev.c:2247 [inline] __netif_receive_skb_core+0xe19/0x5890 net/core/dev.c:5132 __netif_receive_skb_one_core net/core/dev.c:5279 [inline] __netif_receive_skb net/core/dev.c:5395 [inline] process_backlog+0x605/0x14e0 net/core/dev.c:6239 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 Local variable ----regs@__bpf_prog_run32 created at: __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681 =====================================================