[PATCH] nfc: Add sockaddr length checks before accessing sa_family in bind handlers
From: Mateusz Jurczyk <hidden>
Date: 2017-06-13 16:44:34
Also in:
linux-wireless, lkml
Subsystem:
networking [general], nfc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Heidelberg, Linus Torvalds
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 <redacted> --- net/nfc/llcp_sock.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index 2ffb18e73df6..80cf35ed320a 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);
--
2.13.1.508.gb3defc5cc-goog