===================================================== BUG: KMSAN: uninit-value in packet_rcv_fanout+0x2442/0x25c0 net/packet/af_packet.c:1463 CPU: 0 PID: 12815 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 packet_rcv_fanout+0x2442/0x25c0 net/packet/af_packet.c:1463 deliver_skb net/core/dev.c:2168 [inline] dev_queue_xmit_nit+0x862/0x1270 net/core/dev.c:2238 xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x20f/0xab0 net/core/dev.c:3493 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4052 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4085 neigh_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip_finish_output2+0x20fd/0x2610 net/ipv4/ip_output.c:228 __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_output+0x593/0x680 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:435 [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:891 udp_sendmsg+0x3bb5/0x4100 net/ipv4/udp.c:1178 inet_sendmsg+0x276/0x2e0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x1056/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmmsg+0x863/0xd60 net/socket.c:2499 __compat_sys_sendmmsg net/compat.c:672 [inline] __do_compat_sys_sendmmsg net/compat.c:679 [inline] __se_compat_sys_sendmmsg+0xcd/0xf0 net/compat.c:676 __ia32_compat_sys_sendmmsg+0x56/0x70 net/compat.c:676 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: 0023:0xf7f41dd9 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:00000000f5d1b0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000159 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020007fc0 RDX: 00000000000001a8 RSI: 0000000000000000 RDI: 0000000000000000 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 ___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:545 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:599 [inline] bpf_prog_run_clear_cb include/linux/filter.h:721 [inline] fanout_demux_bpf net/packet/af_packet.c:1404 [inline] packet_rcv_fanout+0x51e/0x25c0 net/packet/af_packet.c:1456 deliver_skb net/core/dev.c:2168 [inline] dev_queue_xmit_nit+0x862/0x1270 net/core/dev.c:2238 xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x20f/0xab0 net/core/dev.c:3493 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4052 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4085 neigh_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip_finish_output2+0x20fd/0x2610 net/ipv4/ip_output.c:228 __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_output+0x593/0x680 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:435 [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:891 udp_sendmsg+0x3bb5/0x4100 net/ipv4/udp.c:1178 inet_sendmsg+0x276/0x2e0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x1056/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmmsg+0x863/0xd60 net/socket.c:2499 __compat_sys_sendmmsg net/compat.c:672 [inline] __do_compat_sys_sendmmsg net/compat.c:679 [inline] __se_compat_sys_sendmmsg+0xcd/0xf0 net/compat.c:676 __ia32_compat_sys_sendmmsg+0x56/0x70 net/compat.c:676 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 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 =====================================================