KMSAN: uninit-value in gre

KMSAN: uninit-value in gre_rcv (2)
Status: upstream: reported C repro on 2018/09/26 15:04
Reported-by: syzbot+841c053d026900055032@syzkaller.appspotmail.com
First crash: 896d, last: 733d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KMSAN: uninit-value in gre_rcv	C			168	1007d	1048d	0/21	closed as invalid on 2018/07/11 17:18

Sample crash report:

IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
==================================================================
BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:59 [inline]
BUG: KMSAN: uninit-value in erspan_rcv net/ipv4/ip_gre.c:285 [inline]
BUG: KMSAN: uninit-value in gre_rcv+0x11d0/0x1920 net/ipv4/ip_gre.c:425
CPU: 0 PID: 4713 Comm: syz-executor382 Not tainted 4.19.0-rc4+ #58
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+0x2f6/0x430 lib/dump_stack.c:113
 kmsan_report+0x183/0x2b0 mm/kmsan/kmsan.c:917
 __msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:500
 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
 __fswab32 include/uapi/linux/swab.h:59 [inline]
 erspan_rcv net/ipv4/ip_gre.c:285 [inline]
 gre_rcv+0x11d0/0x1920 net/ipv4/ip_gre.c:425
 gre_rcv+0x2d5/0x3b0 net/ipv4/gre_demux.c:142
 ip_local_deliver_finish+0x90e/0xfa0 net/ipv4/ip_input.c:215
 NF_HOOK include/linux/netfilter.h:287 [inline]
 ip_local_deliver+0x438/0x4d0 net/ipv4/ip_input.c:256
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:415 [inline]
 NF_HOOK include/linux/netfilter.h:287 [inline]
 ip_rcv+0x65f/0x6d0 net/ipv4/ip_input.c:524
 __netif_receive_skb_one_core net/core/dev.c:4891 [inline]
 __netif_receive_skb net/core/dev.c:5001 [inline]
 process_backlog+0xd89/0x11a0 net/core/dev.c:5807
 napi_poll net/core/dev.c:6227 [inline]
 net_rx_action+0x935/0x1c00 net/core/dev.c:6293
 __do_softirq+0x614/0xa72 kernel/softirq.c:292
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1055
 </IRQ>
 do_softirq kernel/softirq.c:336 [inline]
 __local_bh_enable_ip+0x119/0x150 kernel/softirq.c:189
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:723 [inline]
 ip_finish_output2+0x13cd/0x14f0 net/ipv4/ip_output.c:231
 ip_do_fragment+0x37b8/0x3fd0 net/ipv4/ip_output.c:678
 ip_fragment+0x249/0x3f0 net/ipv4/ip_output.c:561
 ip_finish_output+0xfbb/0x10a0 net/ipv4/ip_output.c:315
 NF_HOOK_COND include/linux/netfilter.h:276 [inline]
 ip_output+0x50f/0x5d0 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out net/ipv4/ip_output.c:124 [inline]
 ip_send_skb+0x178/0x350 net/ipv4/ip_output.c:1441
 udp_send_skb+0x10b9/0x18d0 net/ipv4/udp.c:829
 udp_push_pending_frames net/ipv4/udp.c:857 [inline]
 udp_sendmsg+0xac6/0x3cd0 net/ipv4/udp.c:1148
 udpv6_sendmsg+0x12e2/0x4cf0 net/ipv6/udp.c:1196
 inet_sendmsg+0x4c5/0x7d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x868/0xa30 net/socket.c:1786
 __do_sys_sendto net/socket.c:1798 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1794
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1794
 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441319
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff698f4638 EFLAGS: 00000286 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000441319
RDX: 000000000000000e RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00000000006cc018 R08: 0000000020000180 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000402280
R13: 0000000000402310 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:270 [inline]
 kmsan_internal_chain_origin+0x128/0x210 mm/kmsan/kmsan.c:572
 kmsan_memcpy_origins+0x13d/0x1b0 mm/kmsan/kmsan.c:396
 __msan_memcpy+0xc3/0x130 mm/kmsan/kmsan_instr.c:286
 pskb_expand_head+0x49f/0x1e10 net/core/skbuff.c:1470
 __skb_cow include/linux/skbuff.h:2911 [inline]
 skb_cow_head include/linux/skbuff.h:2945 [inline]
 ip_tunnel_xmit+0x3217/0x3870 net/ipv4/ip_tunnel.c:771
 __gre_xmit net/ipv4/ip_gre.c:454 [inline]
 erspan_xmit+0x1af6/0x3380 net/ipv4/ip_gre.c:752
 __netdev_start_xmit include/linux/netdevice.h:4287 [inline]
 netdev_start_xmit include/linux/netdevice.h:4296 [inline]
 xmit_one net/core/dev.c:3216 [inline]
 dev_hard_start_xmit+0x68b/0xd50 net/core/dev.c:3232
 sch_direct_xmit+0x52b/0x860 net/sched/sch_generic.c:327
 qdisc_restart net/sched/sch_generic.c:390 [inline]
 __qdisc_run+0x1ab7/0x3490 net/sched/sch_generic.c:398
 qdisc_run include/net/pkt_sched.h:120 [inline]
 __dev_xmit_skb net/core/dev.c:3411 [inline]
 __dev_queue_xmit+0x1bc3/0x3c60 net/core/dev.c:3770
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3835
 neigh_resolve_output+0xaa2/0xb40 net/core/neighbour.c:1364
 neigh_output include/net/neighbour.h:483 [inline]
 ip_finish_output2+0x13b7/0x14f0 net/ipv4/ip_output.c:229
 ip_do_fragment+0x37b8/0x3fd0 net/ipv4/ip_output.c:678
 ip_fragment+0x249/0x3f0 net/ipv4/ip_output.c:561
 ip_finish_output+0xfbb/0x10a0 net/ipv4/ip_output.c:315
 NF_HOOK_COND include/linux/netfilter.h:276 [inline]
 ip_output+0x50f/0x5d0 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out net/ipv4/ip_output.c:124 [inline]
 ip_send_skb+0x178/0x350 net/ipv4/ip_output.c:1441
 udp_send_skb+0x10b9/0x18d0 net/ipv4/udp.c:829
 udp_push_pending_frames net/ipv4/udp.c:857 [inline]
 udp_sendmsg+0xac6/0x3cd0 net/ipv4/udp.c:1148
 udpv6_sendmsg+0x12e2/0x4cf0 net/ipv6/udp.c:1196
 inet_sendmsg+0x4c5/0x7d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x868/0xa30 net/socket.c:1786
 __do_sys_sendto net/socket.c:1798 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1794
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1794
 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:180
 kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:91
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:100
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2718 [inline]
 __kmalloc_node_track_caller+0xb55/0x1380 mm/slub.c:4351
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x40d/0xe50 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:996 [inline]
 alloc_skb_with_frags+0x1d0/0xac0 net/core/skbuff.c:5273
 sock_alloc_send_pskb+0xe28/0x1420 net/core/sock.c:2082
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2099
 __ip_append_data+0x2d54/0x4460 net/ipv4/ip_output.c:981
 ip_append_data+0x2fb/0x440 net/ipv4/ip_output.c:1196
 udp_sendmsg+0x6f9/0x3cd0 net/ipv4/udp.c:1142
 udpv6_sendmsg+0x12e2/0x4cf0 net/ipv6/udp.c:1196
 inet_sendmsg+0x4c5/0x7d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x868/0xa30 net/socket.c:1786
 __do_sys_sendto net/socket.c:1798 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1794
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1794
 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================

Crashes (146):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kmsan-gce	2018/09/26 07:43	https://github.com/google/kmsan.git master	eb2e6759	b7e11289	.config	log	report	syz	C
ci-upstream-kmsan-gce	2018/11/08 08:57	https://github.com/google/kmsan.git master	7438a3b2	e85d2a61	.config	log	report	syz
ci-upstream-kmsan-gce	2019/03/05 10:25	https://github.com/google/kmsan.git master	fa1981be	bb91cf81	.config	log	report
ci-upstream-kmsan-gce	2019/03/05 06:44	https://github.com/google/kmsan.git master	fa1981be	bb91cf81	.config	log	report
ci-upstream-kmsan-gce	2019/02/22 19:58	https://github.com/google/kmsan.git master	fa1981be	6a5fcca4	.config	log	report
ci-upstream-kmsan-gce	2019/02/22 00:40	https://github.com/google/kmsan.git master	fa1981be	7ff74a98	.config	log	report
ci-upstream-kmsan-gce	2019/02/22 00:30	https://github.com/google/kmsan.git master	fa1981be	7ff74a98	.config	log	report
ci-upstream-kmsan-gce	2019/02/21 19:42	https://github.com/google/kmsan.git master	fa1981be	3133098b	.config	log	report
ci-upstream-kmsan-gce	2019/02/18 17:32	https://github.com/google/kmsan.git master	fa1981be	59f36113	.config	log	report
ci-upstream-kmsan-gce	2019/02/18 15:31	https://github.com/google/kmsan.git master	fa1981be	59f36113	.config	log	report
ci-upstream-kmsan-gce	2019/02/17 15:43	https://github.com/google/kmsan.git master	fa1981be	3e98cc30	.config	log	report
ci-upstream-kmsan-gce	2019/02/14 11:51	https://github.com/google/kmsan.git master	fa1981be	6a46f448	.config	log	report
ci-upstream-kmsan-gce	2019/02/13 18:06	https://github.com/google/kmsan.git master	fa1981be	0a49c954	.config	log	report
ci-upstream-kmsan-gce	2019/02/11 16:35	https://github.com/google/kmsan.git master	fa1981be	73f5f452	.config	log	report
ci-upstream-kmsan-gce	2019/02/09 09:05	https://github.com/google/kmsan.git master	fa1981be	fa6c7b70	.config	log	report
ci-upstream-kmsan-gce	2019/02/08 02:06	https://github.com/google/kmsan.git master	fa1981be	aa4feb03	.config	log	report
ci-upstream-kmsan-gce	2019/02/06 21:34	https://github.com/google/kmsan.git master	fa1981be	d25487bc	.config	log	report
ci-upstream-kmsan-gce	2019/01/27 08:50	https://github.com/google/kmsan.git master	02f2d5ae	c73f090a	.config	log	report
ci-upstream-kmsan-gce	2019/01/06 05:23	https://github.com/google/kmsan.git master	11587f6e	53be0a37	.config	log	report
ci-upstream-kmsan-gce	2018/12/31 00:23	https://github.com/google/kmsan.git master	8ba10281	2b42fdc8	.config	log	report
ci-upstream-kmsan-gce	2018/12/24 22:23	https://github.com/google/kmsan.git master	79fc24ff	8a41a0ad	.config	log	report
ci-upstream-kmsan-gce	2018/12/23 03:05	https://github.com/google/kmsan.git master	75b3ad22	e3bd7ab8	.config	log	report
ci-upstream-kmsan-gce	2018/12/22 13:37	https://github.com/google/kmsan.git master	75b3ad22	e3bd7ab8	.config	log	report
ci-upstream-kmsan-gce	2018/12/13 05:36	https://github.com/google/kmsan.git master	42db043b	02613a41	.config	log	report
ci-upstream-kmsan-gce	2018/12/11 23:12	https://github.com/google/kmsan.git master	42db043b	7795ae03	.config	log	report
ci-upstream-kmsan-gce	2018/12/10 00:12	https://github.com/google/kmsan.git master	3f06bda6	96cc4c50	.config	log	report
ci-upstream-kmsan-gce	2018/12/07 00:43	https://github.com/google/kmsan.git master	f39a9684	dcf836b1	.config	log	report
ci-upstream-kmsan-gce	2018/12/04 11:05	https://github.com/google/kmsan.git master	8f22beb7	6ad0ae61	.config	log	report
ci-upstream-kmsan-gce	2018/12/02 19:38	https://github.com/google/kmsan.git master	9fbf73b8	e0d8c853	.config	log	report
ci-upstream-kmsan-gce	2018/12/01 00:47	https://github.com/google/kmsan.git master	3a686988	ade12e91	.config	log	report
ci-upstream-kmsan-gce	2018/11/30 11:39	https://github.com/google/kmsan.git master	c1c8fce4	66071e27	.config	log	report
ci-upstream-kmsan-gce	2018/11/30 02:44	https://github.com/google/kmsan.git master	c1c8fce4	66071e27	.config	log	report
ci-upstream-kmsan-gce	2018/11/29 08:42	https://github.com/google/kmsan.git master	fffec98a	4b6d14f2	.config	log	report
ci-upstream-kmsan-gce	2018/11/28 13:46	https://github.com/google/kmsan.git master	fffec98a	4b6d14f2	.config	log	report
ci-upstream-kmsan-gce	2018/11/28 11:38	https://github.com/google/kmsan.git master	fffec98a	4b6d14f2	.config	log	report
ci-upstream-kmsan-gce	2018/11/27 23:49	https://github.com/google/kmsan.git master	fffec98a	4b6d14f2	.config	log	report
ci-upstream-kmsan-gce	2018/11/25 05:40	https://github.com/google/kmsan.git master	fffec98a	ecc7c870	.config	log	report
ci-upstream-kmsan-gce	2018/11/23 13:42	https://github.com/google/kmsan.git master	f97a6c29	2b0dc848	.config	log	report
ci-upstream-kmsan-gce	2018/11/22 11:05	https://github.com/google/kmsan.git master	3ededcaa	2ee77802	.config	log	report
ci-upstream-kmsan-gce	2018/11/22 06:12	https://github.com/google/kmsan.git master	3ededcaa	9db828b5	.config	log	report
ci-upstream-kmsan-gce	2018/11/21 12:47	https://github.com/google/kmsan.git master	598a88bc	5d9a3924	.config	log	report
ci-upstream-kmsan-gce	2018/11/20 21:00	https://github.com/google/kmsan.git master	0891758b	9aca6b52	.config	log	report
ci-upstream-kmsan-gce	2018/11/20 00:58	https://github.com/google/kmsan.git master	2808e543	adf636a8	.config	log	report
ci-upstream-kmsan-gce	2018/11/18 23:49	https://github.com/google/kmsan.git master	cddc5264	adf636a8	.config	log	report
ci-upstream-kmsan-gce	2018/11/18 21:20	https://github.com/google/kmsan.git master	cddc5264	adf636a8	.config	log	report
ci-upstream-kmsan-gce	2018/11/18 16:14	https://github.com/google/kmsan.git master	cddc5264	adf636a8	.config	log	report
ci-upstream-kmsan-gce	2018/09/23 01:11	https://github.com/google/kmsan.git master	7ace4303	37079712	.config	log	report