From fde1375e373137ac52d0530b819bf9df64ab14c1 Mon Sep 17 00:00:00 2001 From: Alan Coopersmith Date: Sun, 26 Jan 2014 10:54:41 -0800 Subject: [PATCH 24/40] Xi: unvalidated lengths in Xinput extension [CVE-2014-8095] Multiple functions in the Xinput extension handling of requests from clients failed to check that the length of the request sent by the client was large enough to perform all the required operations and thus could read or write to memory outside the bounds of the request buffer. This commit includes the creation of a new REQUEST_AT_LEAST_EXTRA_SIZE macro in include/dix.h for the common case of needing to ensure a request is large enough to include both the request itself and a minimum amount of extra data following the request header. v2: backport to nx-libs 3.6.x (Mike DePaulo) Signed-off-by: Alan Coopersmith Reviewed-by: Peter Hutterer Conflicts: Xi/chgdctl.c Xi/chgfctl.c Xi/xiallowev.c Xi/xichangecursor.c Xi/xichangehierarchy.c Xi/xigetclientpointer.c Xi/xigrabdev.c Xi/xipassivegrab.c Xi/xiproperty.c Xi/xiquerydevice.c Xi/xiquerypointer.c Xi/xiselectev.c Xi/xisetclientpointer.c Xi/xisetdevfocus.c Xi/xiwarppointer.c [RHEL5: Xi/xi* files are XI2 ] --- nx-X11/programs/Xserver/Xi/chgdctl.c | 4 ++-- nx-X11/programs/Xserver/Xi/chgfctl.c | 2 ++ nx-X11/programs/Xserver/Xi/sendexev.c | 3 +++ nx-X11/programs/Xserver/include/dix.h | 4 ++++ 4 files changed, 11 insertions(+), 2 deletions(-) diff --git a/nx-X11/programs/Xserver/Xi/chgdctl.c b/nx-X11/programs/Xserver/Xi/chgdctl.c index 63a3c9c..144a51e 100644 --- a/nx-X11/programs/Xserver/Xi/chgdctl.c +++ b/nx-X11/programs/Xserver/Xi/chgdctl.c @@ -87,7 +87,7 @@ SProcXChangeDeviceControl(client) REQUEST(xChangeDeviceControlReq); swaps(&stuff->length, n); - REQUEST_AT_LEAST_SIZE(xChangeDeviceControlReq); + REQUEST_AT_LEAST_EXTRA_SIZE(xChangeDeviceControlReq, sizeof(xDeviceCtl)); swaps(&stuff->control, n); return(ProcXChangeDeviceControl(client)); } @@ -111,7 +111,7 @@ ProcXChangeDeviceControl(client) CARD32 *resolution; REQUEST(xChangeDeviceControlReq); - REQUEST_AT_LEAST_SIZE(xChangeDeviceControlReq); + REQUEST_AT_LEAST_EXTRA_SIZE(xChangeDeviceControlReq, sizeof(xDeviceCtl)); len = stuff->length - (sizeof(xChangeDeviceControlReq) >>2); dev = LookupDeviceIntRec (stuff->deviceid); diff --git a/nx-X11/programs/Xserver/Xi/chgfctl.c b/nx-X11/programs/Xserver/Xi/chgfctl.c index fe8bd1f..3ffac39 100644 --- a/nx-X11/programs/Xserver/Xi/chgfctl.c +++ b/nx-X11/programs/Xserver/Xi/chgfctl.c @@ -160,6 +160,8 @@ ProcXChangeFeedbackControl(client) xStringFeedbackCtl *f = ((xStringFeedbackCtl *) &stuff[1]); if (client->swapped) { + if (len < (sizeof(xStringFeedbackCtl) + 3) >> 2) + return BadLength; swaps(&f->num_keysyms,n); } if (len != ((sizeof(xStringFeedbackCtl)>>2) + f->num_keysyms)) diff --git a/nx-X11/programs/Xserver/Xi/sendexev.c b/nx-X11/programs/Xserver/Xi/sendexev.c index 9b441f2..0b2a701 100644 --- a/nx-X11/programs/Xserver/Xi/sendexev.c +++ b/nx-X11/programs/Xserver/Xi/sendexev.c @@ -154,6 +154,9 @@ ProcXSendExtensionEvent (client) return Success; } + if (stuff->num_events == 0) + return ret; + /* The client's event type must be one defined by an extension. */ first = ((xEvent *) &stuff[1]); diff --git a/nx-X11/programs/Xserver/include/dix.h b/nx-X11/programs/Xserver/include/dix.h index d82979c..9fe575e 100644 --- a/nx-X11/programs/Xserver/include/dix.h +++ b/nx-X11/programs/Xserver/include/dix.h @@ -73,6 +73,10 @@ SOFTWARE. if ((sizeof(req) >> 2) > client->req_len )\ return(BadLength) +#define REQUEST_AT_LEAST_EXTRA_SIZE(req, extra) \ + if (((sizeof(req) + ((uint64_t) extra)) >> 2) > client->req_len ) \ + return(BadLength) + #define REQUEST_FIXED_SIZE(req, n)\ if (((sizeof(req) >> 2) > client->req_len) || \ ((n >> 2) >= client->req_len) || \ -- 2.1.4