From f6a5885fc4d68e7f25ffb42b9d8d80aebb3bacbb Mon Sep 17 00:00:00 2001 From: Mateusz Jurczyk Date: Tue, 13 Jun 2017 18:44:28 +0200 Subject: NFC: Add sockaddr length checks before accessing sa_family in bind handlers 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 --- net/nfc/llcp_sock.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/nfc') diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index d0d12bea65cb..fb7afcaa3004 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -77,7 +77,8 @@ 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); @@ -151,7 +152,8 @@ 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); -- cgit v1.2.3