===================================================== BUG: KMSAN: uninit-value in on_stack arch/x86/include/asm/stacktrace.h:46 [inline] BUG: KMSAN: uninit-value in update_stack_state+0x4bf/0xb40 arch/x86/kernel/unwind_frame.c:218 CPU: 1 PID: 13344 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 on_stack arch/x86/include/asm/stacktrace.h:46 [inline] update_stack_state+0x4bf/0xb40 arch/x86/kernel/unwind_frame.c:218 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+0x4aa/0x1b00 net/core/skbuff.c:1638 skb_unclone include/linux/skbuff.h:1622 [inline] inet_frag_reasm_prepare+0xdc8/0x1420 net/ipv4/inet_fragment.c:439 ip6_frag_reasm net/ipv6/reassembly.c:263 [inline] ip6_frag_queue net/ipv6/reassembly.c:216 [inline] ipv6_frag_rcv+0x333d/0x4a00 net/ipv6/reassembly.c:363 ip6_protocol_deliver_rcu+0x181b/0x22c0 net/ipv6/ip6_input.c:433 ip6_input_finish net/ipv6/ip6_input.c:474 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip6_input net/ipv6/ip6_input.c:483 [inline] ip6_mc_input+0xdf2/0x1460 net/ipv6/ip6_input.c:577 dst_input include/net/dst.h:449 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core net/core/dev.c:5281 [inline] __netif_receive_skb net/core/dev.c:5395 [inline] process_backlog+0x72c/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_instrument_asm_store+0xfd/0x120 mm/kmsan/kmsan_instr.c:78 Code: 89 df 4c 89 f6 31 d2 e8 91 f3 ff ff be ff ff ff ff 65 0f c1 35 44 e5 31 59 ff ce 75 1a e8 bb 70 2e ff 4c 89 7d e0 ff 75 e0 9d <48> 83 c4 10 5b 41 5e 41 5f 5d c3 0f 0b 48 c7 c7 ea 03 2a b4 31 c0 RSP: 0018:ffffb2b08138aef8 EFLAGS: 00000282 RAX: ffffc2b08138af40 RBX: ffffb2b08138af40 RCX: 0000000000000003 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffffb2b08138af40 RBP: ffffb2b08138af20 R08: 0000000000000002 R09: ffffbab08138af40 R10: 0000000000000004 R11: 0000000000000000 R12: ffffa36d1d53c6d8 R13: ffffa36d19aa9b00 R14: 0000000000000008 R15: 0000000000000282 native_save_fl arch/x86/include/asm/irqflags.h:29 [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+0x5d/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 NF_HOOK include/linux/netfilter.h:307 [inline] ip6_finish_output2+0x2339/0x2620 net/ipv6/ip6_output.c:81 ip6_fragment+0x24a9/0x3950 net/ipv6/ip6_output.c:861 __ip6_finish_output+0x73a/0x8e0 net/ipv6/ip6_output.c:141 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] ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179 ip6_send_skb+0xfa/0x390 net/ipv6/ip6_output.c:1865 udp_v6_send_skb+0x1834/0x1e80 net/ipv6/udp.c:1175 udp_v6_push_pending_frames net/ipv6/udp.c:1208 [inline] udpv6_sendmsg+0x1d6d/0x4940 net/ipv6/udp.c:1500 inet6_sendmsg+0x276/0x2e0 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] sock_write_iter+0x4eb/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: 0033:0x45c1f9 Code: Bad RIP value. RSP: 002b:00007f5e7506ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000000370c0 RCX: 000000000045c1f9 RDX: 000000000000ffdc RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 0000000000c9fb6f R14: 00007f5e7506b9c0 R15: 000000000078bf0c Local variable ----acpar@ip6t_do_table created at: ip6t_do_table+0xc3/0x2ac0 net/ipv6/netfilter/ip6_tables.c:263 ip6t_do_table+0xc3/0x2ac0 net/ipv6/netfilter/ip6_tables.c:263 =====================================================