KMSAN: uninit-value in __skb_checksum

KMSAN: uninit-value in __skb_checksum_complete (2)
Status: closed as invalid on 2018/09/05 16:20
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1041d, last: 1040d

similar bugs (4):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
upstream	KMSAN: uninit-value in __skb_checksum_complete (3)		7	748d	914d	0/22	auto-closed as invalid on 2019/10/19 05:22
upstream	KMSAN: uninit-value in __skb_checksum_complete (5)	C	34	12d	267d	0/22	upstream: reported C repro on 2020/08/14 15:09
upstream	KMSAN: uninit-value in __skb_checksum_complete (4)	C	420	290d	532d	0/22	closed as invalid on 2020/07/22 16:42
upstream	KMSAN: uninit-value in __skb_checksum_complete	C	5	1112d	1113d	0/22	closed as invalid on 2018/04/22 15:44

Sample crash report:

IPVS: ftp: loaded support on port[0] = 21
netlink: 'syz-executor4': attribute type 5 has an invalid length.
program syz-executor6 is using a deprecated SCSI ioctl, please convert it to SG_IO
==================================================================
BUG: KMSAN: uninit-value in __skb_checksum_complete+0x30e/0x430 net/core/datagram.c:756
CPU: 0 PID: 8 Comm: ksoftirqd/0 Not tainted 4.17.0+ #17
IPVS: ftp: loaded support on port[0] = 21
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+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
 __skb_checksum_complete+0x30e/0x430 net/core/datagram.c:756
 __skb_checksum_validate_complete include/linux/skbuff.h:3702 [inline]
 icmp_rcv+0xf1f/0x1a00 net/ipv4/icmp.c:1027
IPVS: ftp: loaded support on port[0] = 21
 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]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
 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
 run_ksoftirqd+0x24/0x40 kernel/softirq.c:649
 smpboot_thread_fn+0x4ac/0x9a0 kernel/smpboot.c:164
 kthread+0x4db/0x6c0 kernel/kthread.c:241
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:415

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:287 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:302 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:692
 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:535
 __msan_memcpy+0xda/0x130 mm/kmsan/kmsan_instr.c:427
 csum_partial_copy+0xbd/0x520 lib/checksum.c:178
 skb_copy_and_csum_bits+0x21d/0x10c0 net/core/skbuff.c:2566
 icmp_glue_bits+0x164/0x370 net/ipv4/icmp.c:357
 __ip_append_data+0x3576/0x4020 net/ipv4/ip_output.c:1018
 ip_append_data+0x2fb/0x440 net/ipv4/ip_output.c:1181
 icmp_push_reply+0x23f/0x830 net/ipv4/icmp.c:375
 icmp_send+0x242e/0x2dc0 net/ipv4/icmp.c:741
 ipv4_link_failure+0x5b/0x210 net/ipv4/route.c:1199
 dst_link_failure include/net/dst.h:427 [inline]
 arp_error_report+0x106/0x1a0 net/ipv4/arp.c:297
 neigh_invalidate+0x38b/0x940 net/core/neighbour.c:891
 neigh_timer_handler+0xd8e/0x12e0 net/core/neighbour.c:977
 call_timer_fn+0x280/0x5d0 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0xd96/0x11b0 kernel/time/timer.c:1666
 run_timer_softirq+0x43/0x70 kernel/time/timer.c:1692
 __do_softirq+0x592/0x979 kernel/softirq.c:285

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:287 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:197
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:323
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:330
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb35/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb_fclone include/linux/skbuff.h:1030 [inline]
 sk_stream_alloc_skb+0x17c/0xcf0 net/ipv4/tcp.c:875
 tcp_fragment+0x425/0x20e0 net/ipv4/tcp_output.c:1316
 tcp_write_wakeup+0x1505/0x1ea0 net/ipv4/tcp_output.c:3694
 tcp_send_probe0+0x7c/0x680 net/ipv4/tcp_output.c:3723
 tcp_probe_timer net/ipv4/tcp_timer.c:359 [inline]
 tcp_write_timer_handler+0xe76/0xef0 net/ipv4/tcp_timer.c:577
 tcp_write_timer+0x12b/0x280 net/ipv4/tcp_timer.c:593
 call_timer_fn+0x280/0x5d0 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0xd96/0x11b0 kernel/time/timer.c:1666
 run_timer_softirq+0x43/0x70 kernel/time/timer.c:1692
 __do_softirq+0x592/0x979 kernel/softirq.c:285
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kmsan-gce	2018/07/04 03:43	https://github.com/google/kmsan.git master	4ca559bb	317fc8ea	.config	log	report
ci-upstream-kmsan-gce	2018/07/02 22:59	https://github.com/google/kmsan.git master	6c3632ff	574780b0	.config	log	report