From: Mateusz Jurczyk Date: Tue, 13 Jun 2017 16:44:28 +0000 (+0200) Subject: NFC: Add sockaddr length checks before accessing sa_family in bind handlers X-Git-Tag: C0P2-H0.0--20200415~8121 X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=244a7db0e9d584af63e1cfe4911d3200d1b180ee;p=linux.git NFC: Add sockaddr length checks before accessing sa_family in bind handlers 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 Signed-off-by: Samuel Ortiz Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 19c2ca1a1548..e31dea17473d 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -76,7 +76,8 @@ static int llcp_sock_bind(struct socket *sock, struct sockaddr *addr, int alen) 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 socket *sock, struct sockaddr *addr, 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);