4.9-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);