KMSAN: uninit-value in fib_create_info

Status: fixed on 2018/05/08 18:30
Subsystems: net
[Documentation on labels]
Fix commit: b1993a2de12c net: fix rtnh_ok()
First crash: 3031d, last: 3025d

Sample crash report:
==================================================================
BUG: KMSAN: uninit-value in rtnh_ok include/net/nexthop.h:11 [inline]
BUG: KMSAN: uninit-value in fib_count_nexthops net/ipv4/fib_semantics.c:469 [inline]
BUG: KMSAN: uninit-value in fib_create_info+0x554/0x8d20 net/ipv4/fib_semantics.c:1091
CPU: 1 PID: 3561 Comm: syzkaller095785 Not tainted 4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 rtnh_ok include/net/nexthop.h:11 [inline]
 fib_count_nexthops net/ipv4/fib_semantics.c:469 [inline]
 fib_create_info+0x554/0x8d20 net/ipv4/fib_semantics.c:1091
 fib_table_insert+0x3b6/0x2820 net/ipv4/fib_trie.c:1142
 inet_rtm_newroute+0x210/0x340 net/ipv4/fib_frontend.c:779
 rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4635
 netlink_rcv_skb+0x355/0x5f0 net/netlink/af_netlink.c:2447
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4653
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x1672/0x1750 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x1048/0x1310 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg net/socket.c:640 [inline]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
 __sys_sendmsg net/socket.c:2080 [inline]
 SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
 SyS_sendmsg+0x54/0x80 net/socket.c:2087
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x43fde9
RSP: 002b:00007fff4519f778 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fde9
RDX: 0000000000000000 RSI: 000000002000bfc8 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401710
R13: 00000000004017a0 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321
 slab_post_alloc_hook mm/slab.h:445 [inline]
 slab_alloc_node mm/slub.c:2737 [inline]
 __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:984 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline]
 netlink_sendmsg+0x9a6/0x1310 net/netlink/af_netlink.c:1875
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg net/socket.c:640 [inline]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
 __sys_sendmsg net/socket.c:2080 [inline]
 SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
 SyS_sendmsg+0x54/0x80 net/socket.c:2087
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
==================================================================

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/08 13:25 https://github.com/google/kmsan.git master e2ab7e8abba4 77bd5117 .config console log report syz C ci-upstream-kmsan-gce
2018/04/13 16:53 https://github.com/google/kmsan.git master 35ff515e4bda 0a0c5db6 .config console log report ci-upstream-kmsan-gce
2018/04/13 15:46 https://github.com/google/kmsan.git master 35ff515e4bda 0a0c5db6 .config console log report ci-upstream-kmsan-gce
2018/04/11 14:40 https://github.com/google/kmsan.git master 35ff515e4bda 8b8de427 .config console log report ci-upstream-kmsan-gce
2018/04/11 13:41 https://github.com/google/kmsan.git master 35ff515e4bda 8b8de427 .config console log report ci-upstream-kmsan-gce
2018/04/11 11:52 https://github.com/google/kmsan.git master 35ff515e4bda 8b8de427 .config console log report ci-upstream-kmsan-gce
2018/04/11 10:03 https://github.com/google/kmsan.git master 35ff515e4bda 8b8de427 .config console log report ci-upstream-kmsan-gce
2018/04/09 22:57 https://github.com/google/kmsan.git master e2ab7e8abba4 b9f65507 .config console log report ci-upstream-kmsan-gce
2018/04/09 15:59 https://github.com/google/kmsan.git master e2ab7e8abba4 f13fb445 .config console log report ci-upstream-kmsan-gce
2018/04/09 11:32 https://github.com/google/kmsan.git master e2ab7e8abba4 f13fb445 .config console log report ci-upstream-kmsan-gce
2018/04/08 13:03 https://github.com/google/kmsan.git master e2ab7e8abba4 77bd5117 .config console log report ci-upstream-kmsan-gce
2018/04/07 07:51 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
2018/04/07 07:11 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
2018/04/07 05:58 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
2018/04/07 05:33 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
2018/04/07 02:32 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
2018/04/06 23:27 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
2018/04/06 23:25 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
2018/04/06 23:14 https://github.com/google/kmsan.git master e2ab7e8abba4 d613535f .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.