This is an automated email from the git hooks/post-receive script. x2go pushed a commit to branch 3.6.x in repository nx-libs. commit 985ca320f841bd9a3efc484f92436b3d65ec1b31 Author: Alan Coopersmith <alan.coopersmith@oracle.com> Date: Wed Jan 22 23:12:04 2014 -0800 dbe: unvalidated lengths in DbeSwapBuffers calls [CVE-2014-8097] ProcDbeSwapBuffers() has a 32bit (n) length value that it uses to read from a buffer. The length is never validated, which can lead to out of bound reads, and possibly returning the data read from out of bounds to the misbehaving client via an X Error packet. SProcDbeSwapBuffers() swaps data (for correct endianness) before handing it off to the real proc. While doing the swapping, the length field is not validated, which can cause memory corruption. v2: reorder checks to avoid compilers optimizing out checks for overflow that happen after we'd already have done the overflowing multiplications. v3: backport to nx-libs 3.6.x (Mike DePaulo) Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com> Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net> Conflicts: dbe/dbe.c --- nx-X11/programs/Xserver/dbe/dbe.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/nx-X11/programs/Xserver/dbe/dbe.c b/nx-X11/programs/Xserver/dbe/dbe.c index c0d6131..5a1e9b0 100644 --- a/nx-X11/programs/Xserver/dbe/dbe.c +++ b/nx-X11/programs/Xserver/dbe/dbe.c @@ -725,8 +725,8 @@ ProcDbeSwapBuffers(client) DbeSwapInfoPtr swapInfo; xDbeSwapInfo *dbeSwapInfo; int error; - register int i, j; - int nStuff; + unsigned int i, j; + unsigned int nStuff; REQUEST_AT_LEAST_SIZE(xDbeSwapBuffersReq); @@ -734,11 +734,13 @@ ProcDbeSwapBuffers(client) if (nStuff == 0) { + REQUEST_SIZE_MATCH(xDbeSwapBuffersReq); return(Success); } if (nStuff > UINT32_MAX / sizeof(DbeSwapInfoRec)) return BadAlloc; + REQUEST_FIXED_SIZE(xDbeSwapBuffersReq, nStuff * sizeof(xDbeSwapInfo)); /* Get to the swap info appended to the end of the request. */ dbeSwapInfo = (xDbeSwapInfo *)&stuff[1]; @@ -1289,7 +1291,7 @@ SProcDbeSwapBuffers(client) ClientPtr client; { REQUEST(xDbeSwapBuffersReq); - register int i, n; + unsigned int i, n; xDbeSwapInfo *pSwapInfo; @@ -1297,6 +1299,9 @@ SProcDbeSwapBuffers(client) REQUEST_AT_LEAST_SIZE(xDbeSwapBuffersReq); swapl(&stuff->n, n); + if (stuff->n > UINT32_MAX / sizeof(DbeSwapInfoRec)) + return BadAlloc; + REQUEST_FIXED_SIZE(xDbeSwapBuffersReq, stuff->n * sizeof(xDbeSwapInfo)); if (stuff->n != 0) { -- Alioth's /srv/git/_hooks_/post-receive-email on /srv/git/code.x2go.org/nx-libs.git