3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mateusz Jurczyk <mjurczyk@xxxxxxxxxx> commit f6a5885fc4d68e7f25ffb42b9d8d80aebb3bacbb upstream. Verify that the caller-provided sockaddr structure is large enough to contain the sa_family field, before accessing it in bind() handlers of the AF_NFC socket. Since the syscall doesn't enforce a minimum size of the corresponding memory region, very short sockaddrs (zero or one byte long) result in operating on uninitialized memory while referencing .sa_family. Signed-off-by: Mateusz Jurczyk <mjurczyk@xxxxxxxxxx> Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/nfc/llcp_sock.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -76,7 +76,8 @@ static int llcp_sock_bind(struct socket struct sockaddr_nfc_llcp llcp_addr; int len, ret = 0; - if (!addr || addr->sa_family != AF_NFC) + if (!addr || alen < offsetofend(struct sockaddr, sa_family) || + addr->sa_family != AF_NFC) return -EINVAL; pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family); @@ -150,7 +151,8 @@ static int llcp_raw_sock_bind(struct soc struct sockaddr_nfc_llcp llcp_addr; int len, ret = 0; - if (!addr || addr->sa_family != AF_NFC) + if (!addr || alen < offsetofend(struct sockaddr, sa_family) || + addr->sa_family != AF_NFC) return -EINVAL; pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family);