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authorEric Dumazet <edumazet@google.com>2018-06-05 06:06:19 -0700
committerDavid S. Miller <davem@davemloft.net>2018-06-05 12:29:43 -0400
commit5b5e7a0de2bbf2a1afcd9f49e940010e9fb80d53 (patch)
treeaeeb3034fc3558cdfef6a05406ded1dbd57535c8 /net/ipv4/metrics.c
parente783bb00ad86d9d1f01d9d3a750713070036358e (diff)
net: metrics: add proper netlink validation
Before using nla_get_u32(), better make sure the attribute is of the proper size. Code recently was changed, but bug has been there from beginning of git. BUG: KMSAN: uninit-value in rtnetlink_put_metrics+0x553/0x960 net/core/rtnetlink.c:746 CPU: 1 PID: 14139 Comm: syz-executor6 Not tainted 4.17.0-rc5+ #103 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+0x149/0x260 mm/kmsan/kmsan.c:1084 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686 rtnetlink_put_metrics+0x553/0x960 net/core/rtnetlink.c:746 fib_dump_info+0xc42/0x2190 net/ipv4/fib_semantics.c:1361 rtmsg_fib+0x65f/0x8c0 net/ipv4/fib_semantics.c:419 fib_table_insert+0x2314/0x2b50 net/ipv4/fib_trie.c:1287 inet_rtm_newroute+0x210/0x340 net/ipv4/fib_frontend.c:779 rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646 netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg net/socket.c:639 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117 __sys_sendmsg net/socket.c:2155 [inline] __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x455a09 RSP: 002b:00007faae5fd8c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007faae5fd96d4 RCX: 0000000000455a09 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000005d0 R14: 00000000006fdc20 R15: 0000000000000000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline] kmsan_save_stack mm/kmsan/kmsan.c:294 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:685 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:529 fib_convert_metrics net/ipv4/fib_semantics.c:1056 [inline] fib_create_info+0x2d46/0x9dc0 net/ipv4/fib_semantics.c:1150 fib_table_insert+0x3e4/0x2b50 net/ipv4/fib_trie.c:1146 inet_rtm_newroute+0x210/0x340 net/ipv4/fib_frontend.c:779 rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646 netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg net/socket.c:639 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117 __sys_sendmsg net/socket.c:2155 [inline] __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2753 [inline] __kmalloc_node_track_caller+0xb32/0x11b0 mm/slub.c:4395 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:988 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0x76e/0x1350 net/netlink/af_netlink.c:1876 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg net/socket.c:639 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2117 __sys_sendmsg net/socket.c:2155 [inline] __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: a919525ad832 ("net: Move fib_convert_metrics to metrics file") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/metrics.c')
-rw-r--r--net/ipv4/metrics.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/metrics.c b/net/ipv4/metrics.c
index 5121c6475e6b..04311f7067e2 100644
--- a/net/ipv4/metrics.c
+++ b/net/ipv4/metrics.c
@@ -32,6 +32,8 @@ int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len,
if (val == TCP_CA_UNSPEC)
return -EINVAL;
} else {
+ if (nla_len(nla) != sizeof(u32))
+ return -EINVAL;
val = nla_get_u32(nla);
}
if (type == RTAX_ADVMSS && val > 65535 - 40)