From: Kees Cook <keescook@chromium.org>
To: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Potapenko <glider@google.com>,
Kostya Serebryany <kcc@google.com>,
Andrey Konovalov <andreyknvl@google.com>,
Eric Dumazet <edumazet@google.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
security@kernel.org
Subject: [PATCH] net: recvmsg: Unconditionally zero struct sockaddr_storage
Date: Tue, 31 Oct 2017 09:14:45 -0700 [thread overview]
Message-ID: <20171031161445.GA140874@beast> (raw)
Some protocols do not correctly wipe the contents of the on-stack
struct sockaddr_storage sent down into recvmsg() (e.g. SCTP), and leak
kernel stack contents to userspace. This wipes it unconditionally before
per-protocol handlers run.
Note that leaks like this are mitigated by building with
CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
Reported-by: Alexander Potapenko <glider@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
net/socket.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/socket.c b/net/socket.c
index c729625eb5d3..34183f4fbdf8 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2188,6 +2188,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
struct sockaddr __user *uaddr;
int __user *uaddr_len = COMPAT_NAMELEN(msg);
+ memset(&addr, 0, sizeof(addr));
msg_sys->msg_name = &addr;
if (MSG_CMSG_COMPAT & flags)
--
2.7.4
--
Kees Cook
Pixel Security
next reply other threads:[~2017-10-31 16:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-31 16:14 Kees Cook [this message]
2017-10-31 17:31 ` [PATCH] net: recvmsg: Unconditionally zero struct sockaddr_storage Eric Dumazet
2017-11-01 12:48 ` Eric W. Biederman
2017-11-01 18:23 ` Kees Cook
2017-11-15 8:22 ` Alexander Potapenko
2017-11-16 4:17 ` [PATCH net] net/sctp: Always set scope_id in sctp_inet6_skb_msgname Eric W. Biederman
2017-11-16 14:00 ` David Miller
2017-11-15 2:13 ` [PATCH] net: recvmsg: Unconditionally zero struct sockaddr_storage Kees Cook
2017-11-15 18:37 ` Eric W. Biederman
2017-10-31 17:35 ` Ben Hutchings
2017-11-01 6:49 ` Willy Tarreau
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