===================================================== BUG: KMSAN: uninit-value in update_stack_state+0x974/0xb40 arch/x86/kernel/unwind_frame.c:238 CPU: 0 PID: 24483 Comm: syz-executor.2 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 update_stack_state+0x974/0xb40 arch/x86/kernel/unwind_frame.c:238 unwind_next_frame+0x8c6/0xed0 arch/x86/kernel/unwind_frame.c:305 arch_stack_walk+0x33e/0x3e0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x117/0x1a0 kernel/stacktrace.c:123 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116 pskb_expand_head+0x38b/0x1b00 net/core/skbuff.c:1636 __pskb_pull_tail+0x17a/0x1dd0 net/core/skbuff.c:2058 __pskb_pull include/linux/skbuff.h:2296 [inline] pskb_pull include/linux/skbuff.h:2304 [inline] icmp_rcv+0xad8/0x1930 net/ipv4/icmp.c:1062 ip_protocol_deliver_rcu+0x700/0xbc0 net/ipv4/ip_input.c:204 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip_local_deliver+0x62a/0x7c0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:449 [inline] ip_rcv_finish net/ipv4/ip_input.c:428 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip_rcv+0x6cf/0x750 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core net/core/dev.c:5281 [inline] __netif_receive_skb net/core/dev.c:5395 [inline] process_backlog+0xfb5/0x14e0 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 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_call_function_single+0x107/0x130 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:601 RIP: 0010:__msan_poison_alloca+0xe3/0x120 mm/kmsan/kmsan_instr.c:191 Code: 00 e8 11 c8 d0 02 65 44 0f c1 3d 48 e4 f1 51 41 ff cf 75 34 89 c3 e8 bc 6f 2e ff 48 8b 44 24 08 48 89 44 24 10 ff 74 24 10 9d <4c> 89 e7 44 89 f6 89 da e8 10 f5 ff ff 48 8d 65 d8 5b 41 5c 41 5d RSP: 0018:ffffa729164974d0 EFLAGS: 00000246 RAX: 0000000000000246 RBX: 0000000006b70106 RCX: ffffffffad586530 RDX: 0000000000000a20 RSI: 00000000000a0443 RDI: 00000000d08bf23f RBP: ffffa72916497550 R08: 0000000000000002 R09: ffffa72916497508 R10: 0000000000000004 R11: 0000000000000000 R12: ffffa72916497570 R13: 0000000000000001 R14: 0000000000000008 R15: 0000000000000000 native_save_fl kernel/softirq.c:330 [inline] arch_local_save_flags arch/x86/include/asm/irqflags.h:79 [inline] arch_local_irq_save arch/x86/include/asm/irqflags.h:120 [inline] do_softirq+0x50/0x150 kernel/softirq.c:333 netif_rx_ni+0x202/0x3b0 net/core/dev.c:4830 dev_loopback_xmit+0x58a/0x630 net/core/dev.c:3846 ip_mc_finish_output+0x47d/0x6c0 net/ipv4/ip_output.c:355 NF_HOOK include/linux/netfilter.h:307 [inline] ip_mc_output+0x773/0x1090 net/ipv4/ip_output.c:394 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:125 [inline] ip_send_skb net/ipv4/ip_output.c:1560 [inline] ip_push_pending_frames+0x243/0x460 net/ipv4/ip_output.c:1580 raw_sendmsg+0x2e23/0x46d0 net/ipv4/raw.c:672 inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:814 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] sock_write_iter+0x651/0x720 net/socket.c:999 call_write_iter include/linux/fs.h:1908 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0xd98/0x1480 fs/read_write.c:578 ksys_write+0x267/0x450 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:640 __x64_sys_write+0x4a/0x70 fs/read_write.c:640 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:00007f255e619c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000036940 RCX: 000000000045c1d9 RDX: 0000000000000058 RSI: 0000000020000000 RDI: 0000000000000007 RBP: 000000000078bfe0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac R13: 0000000000c9fb6f R14: 00007f255e61a9c0 R15: 000000000078bfac Local variable ----_iph.i@get_l4proto created at: skb_header_pointer net/netfilter/nf_conntrack_core.c:382 [inline] ipv4_get_l4proto net/netfilter/nf_conntrack_core.c:328 [inline] get_l4proto+0xac/0x6f0 net/netfilter/nf_conntrack_core.c:384 skb_header_pointer net/netfilter/nf_conntrack_core.c:382 [inline] ipv4_get_l4proto net/netfilter/nf_conntrack_core.c:328 [inline] get_l4proto+0xac/0x6f0 net/netfilter/nf_conntrack_core.c:384 =====================================================