From 90cc925c5991fcb203f72d00b04419cd754a9b2c Mon Sep 17 00:00:00 2001 From: Alan Coopersmith Date: Fri, 17 Jan 2014 18:54:03 -0800 Subject: unchecked malloc may allow unauthed client to crash Xserver [CVE-2014-8091] authdes_ezdecode() calls malloc() using a length provided by the connection handshake sent by a newly connected client in order to authenticate to the server, so should be treated as untrusted. It didn't check if malloc() failed before writing to the newly allocated buffer, so could lead to a server crash if the server fails to allocate memory (up to UINT16_MAX bytes, since the len field is a CARD16 in the X protocol). Reported-by: Ilja Van Sprundel Signed-off-by: Alan Coopersmith Reviewed-by: Peter Hutterer --- os/rpcauth.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/os/rpcauth.c b/os/rpcauth.c index d60ea3518..413cc6118 100644 --- a/os/rpcauth.c +++ b/os/rpcauth.c @@ -66,6 +66,10 @@ authdes_ezdecode(const char *inmsg, int len) SVCXPRT xprt; temp_inmsg = malloc(len); + if (temp_inmsg == NULL) { + why = AUTH_FAILED; /* generic error, since there is no AUTH_BADALLOC */ + return NULL; + } memmove(temp_inmsg, inmsg, len); memset((char *) &msg, 0, sizeof(msg)); -- cgit v1.2.3