===================================================== BUG: KMSAN: uninit-value in ____bpf_skb_get_nlattr net/core/filter.c:144 [inline] BUG: KMSAN: uninit-value in bpf_skb_get_nlattr+0x145/0x290 net/core/filter.c:134 CPU: 0 PID: 28077 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_get_nlattr net/core/filter.c:144 [inline] bpf_skb_get_nlattr+0x145/0x290 net/core/filter.c:134 ___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_save_cb include/linux/filter.h:691 [inline] bpf_prog_run_save_cb include/linux/filter.h:705 [inline] sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119 sk_filter include/linux/filter.h:831 [inline] netlink_unicast+0x4b9/0x1100 net/netlink/af_netlink.c:1331 netlink_ack+0x105c/0x11a0 net/netlink/af_netlink.c:2439 netlink_rcv_skb+0x321/0x650 net/netlink/af_netlink.c:2475 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5478 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x1370/0x1400 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmsg+0x623/0x750 net/socket.c:2439 __do_sys_sendmsg net/socket.c:2448 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2446 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2446 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:00007f412bb3fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000027980 RCX: 000000000045c1d9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 000000000078bfe0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac R13: 0000000000c9fb6f R14: 00007f412bb409c0 R15: 000000000078bfac 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_save_cb include/linux/filter.h:691 [inline] bpf_prog_run_save_cb include/linux/filter.h:705 [inline] sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119 sk_filter include/linux/filter.h:831 [inline] netlink_unicast+0x4b9/0x1100 net/netlink/af_netlink.c:1331 netlink_ack+0x105c/0x11a0 net/netlink/af_netlink.c:2439 netlink_rcv_skb+0x321/0x650 net/netlink/af_netlink.c:2475 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5478 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x1370/0x1400 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmsg+0x623/0x750 net/socket.c:2439 __do_sys_sendmsg net/socket.c:2448 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2446 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2446 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 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_save_cb include/linux/filter.h:691 [inline] bpf_prog_run_save_cb include/linux/filter.h:705 [inline] sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119 sk_filter include/linux/filter.h:831 [inline] netlink_unicast+0x4b9/0x1100 net/netlink/af_netlink.c:1331 netlink_ack+0x105c/0x11a0 net/netlink/af_netlink.c:2439 netlink_rcv_skb+0x321/0x650 net/netlink/af_netlink.c:2475 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5478 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x1370/0x1400 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmsg+0x623/0x750 net/socket.c:2439 __do_sys_sendmsg net/socket.c:2448 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2446 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2446 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 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 =====================================================