syzbot


KMSAN: uninit-value in tcp_v4_do_rcv

Status: closed as invalid on 2018/09/05 16:10
Subsystems: net
[Documentation on labels]
First crash: 2604d, last: 2604d

Sample crash report:
netlink: 8 bytes leftover after parsing attributes in process `syz-executor0'.
==================================================================
BUG: KMSAN: uninit-value in sock_rps_save_rxhash include/net/sock.h:956 [inline]
BUG: KMSAN: uninit-value in tcp_v4_do_rcv+0x4a1/0xd90 net/ipv4/tcp_ipv4.c:1468
CPU: 0 PID: 4527 Comm: sshd Not tainted 4.17.0+ #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1368
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:634
 sock_rps_save_rxhash include/net/sock.h:956 [inline]
 tcp_v4_do_rcv+0x4a1/0xd90 net/ipv4/tcp_ipv4.c:1468
 tcp_v4_rcv+0x676e/0x6cd0 net/ipv4/tcp_ipv4.c:1765
 ip_local_deliver_finish+0x887/0xed0 net/ipv4/ip_input.c:215
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:256
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish+0xa1b/0x1d10 net/ipv4/ip_input.c:396
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x1168/0x16a0 net/ipv4/ip_input.c:492
 __netif_receive_skb_core+0x47f3/0x4aa0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4731
 napi_skb_finish net/core/dev.c:5093 [inline]
 napi_gro_receive+0x6a7/0xb60 net/core/dev.c:5124
 receive_buf+0x4c96/0x6ae0 drivers/net/virtio_net.c:945
 virtnet_receive drivers/net/virtio_net.c:1200 [inline]
 virtnet_poll+0x8ff/0x1420 drivers/net/virtio_net.c:1282
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x766/0x1a80 net/core/dev.c:5801
 __do_softirq+0x592/0x979 kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:366 [inline]
 irq_exit+0x207/0x240 kernel/softirq.c:407
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:525
 do_IRQ+0x17d/0x1c0 arch/x86/kernel/irq.c:264
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:646
 </IRQ>
RIP: 0010:msan_get_shadow_origin_ptr+0x102/0x2c0 include/linux/mmzone.h:1205
RSP: 0018:ffff88019ea3f418 EFLAGS: 00000202 ORIG_RAX: ffffffffffffffd9
RAX: ffff880243f08e14 RBX: ffffffff8b58a000 RCX: ffff88021fff1700
RDX: 0000000000000700 RSI: 0000000000000000 RDI: ffff8801c3f08e14
RBP: ffff88019ea3f460 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff887baaf0 R12: 0000000000000002
R13: ffff8801c3889d40 R14: ffffffff8b589000 R15: ffff8801c3f08e14
 __msan_metadata_ptr_for_load_2+0x10/0x20 mm/kmsan/kmsan_instr.c:332
 tcp_poll+0xb68/0xfa0 net/ipv4/tcp.c:587
 sock_poll+0x340/0x380 net/socket.c:1137
 do_select+0x18e5/0x2bf0 fs/select.c:512
 core_sys_select+0xb1c/0x1080 fs/select.c:655
 kern_select fs/select.c:696 [inline]
 __do_sys_select fs/select.c:705 [inline]
 __se_sys_select+0x24b/0x600 fs/select.c:702
 __x64_sys_select+0x15d/0x1b0 fs/select.c:702
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x7f0a74189dd3
RSP: 002b:00007ffdf9cc00f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000017
RAX: ffffffffffffffda RBX: 00007ffdf9cc0180 RCX: 00007f0a74189dd3
RDX: 000055fa06577ae0 RSI: 000055fa06577b00 RDI: 000000000000000c
RBP: 000055fa062d48dc R08: 00007ffdf9cc0120 R09: 0101010101010101
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdf9cc0188
R13: 0000000000000000 R14: 00007ffdf9cc0178 R15: 00007ffdf9cc017c

Local variable description: ----skb.addr@__netif_receive_skb_core
Variable was created at:
 __netif_receive_skb_core+0xb7/0x4aa0 net/core/dev.c:4462
 __netif_receive_skb net/core/dev.c:4657 [inline]
 netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4731
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/07/04 12:13 https://github.com/google/kmsan.git master 4ca559bbdeaf 317fc8ea .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.