From: Eric Biggers ebiggers@google.com

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 <linux/pfkeyv2.h> #include <sys/socket.h> #include <unistd.h>

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); }

Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers ebiggers@google.com --- 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 596499cc8b2f..d40861a048fe 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -516,6 +516,9 @@ 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;