From: Mathias Krause Date: Wed, 15 Aug 2012 11:31:53 +0000 (+0000) Subject: llc: fix info leak via getsockname() X-Git-Tag: Ubuntu-5.2.0-15.16~17364^2~28 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=3592aaeb80290bda0f2cf0b5456c97bfc638b192;p=mirror_ubuntu-eoan-kernel.git llc: fix info leak via getsockname() 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 --- diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index 8c2919ca36f6..c2190005a114 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -969,14 +969,13 @@ 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)