From 27fb5ec5224d73f8e05a0ec6a00bf6b07a591470 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Wed, 15 Aug 2012 11:31:53 +0000 Subject: llc: fix info leak via getsockname() [ Upstream commit 3592aaeb80290bda0f2cf0b5456c97bfc638b192 ] The LLC code wrongly returns 0, i.e. "success", when the socket is zapped. Together with the uninitialized uaddrlen pointer argument from sys_getsockname this leads to an arbitrary memory leak of up to 128 bytes kernel stack via the getsockname() syscall. Return an error instead when the socket is zapped to prevent the info leak. Also remove the unnecessary memset(0). We don't directly write to the memory pointed by uaddr but memcpy() a local structure at the end of the function that is properly initialized. Signed-off-by: Mathias Krause Cc: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/llc/af_llc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/llc') diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index a18e6c3..99a60d5 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -966,14 +966,13 @@ static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr, struct sockaddr_llc sllc; struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); - int rc = 0; + int rc = -EBADF; memset(&sllc, 0, sizeof(sllc)); lock_sock(sk); if (sock_flag(sk, SOCK_ZAPPED)) goto out; *uaddrlen = sizeof(sllc); - memset(uaddr, 0, *uaddrlen); if (peer) { rc = -ENOTCONN; if (sk->sk_state != TCP_ESTABLISHED) -- cgit v1.1