From e3c42b61ff813921ba58cfc0019e3fd63f651190 Mon Sep 17 00:00:00 2001
From: Mateusz Jurczyk <mjurczyk@google.com>
Date: Fri, 23 Jun 2017 19:32:28 +0200
Subject: [PATCH] af_iucv: Move sockaddr length checks to before accessing sa_family in bind and connect handlers
Git-commit: e3c42b61ff813921ba58cfc0019e3fd63f651190
Patch-mainline: v4.13-rc1
References: bsc#1051510
Verify that the caller-provided sockaddr structure is large enough to
contain the sa_family field, before accessing it in bind() and connect()
handlers of the AF_IUCV socket. Since neither syscall enforces 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.
Fixes: 52a82e23b9f2 ("af_iucv: Validate socket address length in iucv_sock_bind()")
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
[jwi: removed unneeded null-check for addr]
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/iucv/af_iucv.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 05112094d76b..ac033e413bc5 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -715,10 +715,8 @@ static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
char uid[9];
/* Verify the input sockaddr */
- if (!addr || addr->sa_family != AF_IUCV)
- return -EINVAL;
-
- if (addr_len < sizeof(struct sockaddr_iucv))
+ if (addr_len < sizeof(struct sockaddr_iucv) ||
+ addr->sa_family != AF_IUCV)
return -EINVAL;
lock_sock(sk);
@@ -862,7 +860,7 @@ static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
struct iucv_sock *iucv = iucv_sk(sk);
int err;
- if (addr->sa_family != AF_IUCV || alen < sizeof(struct sockaddr_iucv))
+ if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
return -EINVAL;
if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
--
2.16.4