===================================================== 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: 1 PID: 8490 Comm: syz-executor.0 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_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 dev_queue_xmit_nit+0x11a0/0x1280 net/core/dev.c:2355 xmit_one net/core/dev.c:3552 [inline] dev_hard_start_xmit+0x20c/0xa70 net/core/dev.c:3572 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4131 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4164 neigh_hh_output include/net/neighbour.h:498 [inline] neigh_output include/net/neighbour.h:507 [inline] ip6_finish_output2+0x2057/0x2620 net/ipv6/ip6_output.c:117 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:143 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:153 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:176 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0x1047/0x15a0 net/ipv6/ndisc.c:506 ndisc_send_rs+0xbd8/0xc30 net/ipv6/ndisc.c:700 addrconf_rs_timer+0x62f/0xcf0 net/ipv6/addrconf.c:3848 call_timer_fn+0x218/0x510 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers+0xd20/0x11c0 kernel/time/timer.c:1773 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786 __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 invoke_softirq kernel/softirq.c:390 [inline] __irq_exit_rcu+0x226/0x270 kernel/softirq.c:420 irq_exit_rcu+0xe/0x10 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x107/0x130 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:593 RIP: 0010:kmsan_in_runtime mm/kmsan/kmsan.h:75 [inline] RIP: 0010:kmsan_get_shadow_origin_ptr+0x2b/0xb0 mm/kmsan/kmsan_shadow.c:145 Code: 48 89 e5 41 57 41 56 53 41 89 d7 48 89 f1 49 89 fe 48 81 fe 01 10 00 00 73 6b 80 3d 2e ec 6d 0e 00 74 0b 65 8b 05 45 d0 d1 69 <85> c0 74 22 48 c7 c0 00 20 9f a4 48 c7 c3 00 30 9f a4 45 84 ff 48 RSP: 0018:ffffaa5bc39db5f8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000008 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffffa3b29758 RBP: ffffaa5bc39db610 R08: ffffe3cb4000000f R09: ffff9b4cafffb000 R10: 0000000000000000 R11: ffffffffffffffff R12: 0000000000000000 R13: 0000000000000000 R14: ffffffffa3b29758 R15: 0000000000000000 __msan_metadata_ptr_for_load_8+0x10/0x20 mm/kmsan/kmsan_instr.c:55 pmd_pfn include/linux/mm.h:2175 [inline] pte_lockptr include/linux/mm.h:2175 [inline] copy_pte_range mm/memory.c:830 [inline] copy_pmd_range mm/memory.c:902 [inline] copy_pud_range mm/memory.c:936 [inline] copy_p4d_range mm/memory.c:958 [inline] copy_page_range+0x178d/0x3a50 mm/memory.c:1020 dup_mmap+0x126c/0x1d20 kernel/fork.c:610 dup_mm+0x1f2/0x710 kernel/fork.c:1373 copy_mm kernel/fork.c:1429 [inline] copy_process+0x4bd8/0x9cb0 kernel/fork.c:2100 _do_fork+0x24f/0xfb0 kernel/fork.c:2445 __do_sys_clone kernel/fork.c:2601 [inline] __se_sys_clone+0x381/0x3d0 kernel/fork.c:2582 __x64_sys_clone+0x62/0x80 kernel/fork.c:2582 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45a80a Code: Bad RIP value. RSP: 002b:0000000000c9fd60 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000c9fd60 RCX: 000000000045a80a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000c9fda0 R08: 0000000000000001 R09: 0000000001725940 R10: 0000000001725c10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000c9fdf0 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 dev_queue_xmit_nit+0x11a0/0x1280 net/core/dev.c:2355 xmit_one net/core/dev.c:3552 [inline] dev_hard_start_xmit+0x20c/0xa70 net/core/dev.c:3572 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4131 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4164 neigh_hh_output include/net/neighbour.h:498 [inline] neigh_output include/net/neighbour.h:507 [inline] ip6_finish_output2+0x2057/0x2620 net/ipv6/ip6_output.c:117 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:143 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:153 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:176 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0x1047/0x15a0 net/ipv6/ndisc.c:506 ndisc_send_rs+0xbd8/0xc30 net/ipv6/ndisc.c:700 addrconf_rs_timer+0x62f/0xcf0 net/ipv6/addrconf.c:3848 call_timer_fn+0x218/0x510 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers+0xd20/0x11c0 kernel/time/timer.c:1773 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786 __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 dev_queue_xmit_nit+0x11a0/0x1280 net/core/dev.c:2355 xmit_one net/core/dev.c:3552 [inline] dev_hard_start_xmit+0x20c/0xa70 net/core/dev.c:3572 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4131 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4164 neigh_hh_output include/net/neighbour.h:498 [inline] neigh_output include/net/neighbour.h:507 [inline] ip6_finish_output2+0x2057/0x2620 net/ipv6/ip6_output.c:117 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:143 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:153 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:176 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0x1047/0x15a0 net/ipv6/ndisc.c:506 ndisc_send_rs+0xbd8/0xc30 net/ipv6/ndisc.c:700 addrconf_rs_timer+0x62f/0xcf0 net/ipv6/addrconf.c:3848 call_timer_fn+0x218/0x510 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers+0xd20/0x11c0 kernel/time/timer.c:1773 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786 __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 =====================================================