From f6666d38587be5a534badfef0c80e91a2b10ace6 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 29 Dec 2017 18:15:23 -0600 Subject: [PATCH] af_key: fix buffer overread in parse_exthdrs() commit 4e765b4972af7b07adcb1feb16e7a525ce1f6b28 upstream. If a message sent to a PF_KEY socket ended with an incomplete extension header (fewer than 4 bytes remaining), then parse_exthdrs() read past the end of the message, into uninitialized memory. Fix it by returning -EINVAL in this case. Reproducer: #include #include #include int main() { int sock = socket(PF_KEY, SOCK_RAW, PF_KEY_V2); char buf[17] = { 0 }; struct sadb_msg *msg = (void *)buf; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_DELETE; msg->sadb_msg_len = 2; write(sock, buf, 17); } Signed-off-by: Eric Biggers Signed-off-by: Steffen Klassert Signed-off-by: Ben Hutchings --- net/key/af_key.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/key/af_key.c b/net/key/af_key.c index 71cb44cebaf7..fd80164c9af7 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -493,6 +493,9 @@ static int parse_exthdrs(struct sk_buff *skb, const struct sadb_msg *hdr, void * uint16_t ext_type; int ext_len; + if (len < sizeof(*ehdr)) + return -EINVAL; + ext_len = ehdr->sadb_ext_len; ext_len *= sizeof(uint64_t); ext_type = ehdr->sadb_ext_type;