From 747cea16c4de1f48e838e1388301a2e24a3da6c4 Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Fri, 16 Jan 2015 20:08:59 +0100
Subject: [PATCH 1/2] xkb: Don't swap XkbSetGeometry data in the input buffer
The XkbSetGeometry request embeds data which needs to be swapped when the
server and the client have different endianess.
_XkbSetGeometry() invokes functions that swap these data directly in the
input buffer.
However, ProcXkbSetGeometry() may call _XkbSetGeometry() more than once
(if there is more than one keyboard), thus causing on swapped clients the
same data to be swapped twice in memory, further causing a server crash
because the strings lengths on the second time are way off bounds.
To allow _XkbSetGeometry() to run reliably more than once with swapped
clients, do not swap the data in the buffer, use variables instead.
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit 81c90dc8f0aae3b65730409b1b615b5fa7280ebd)
(cherry picked from commit 29be310c303914090298ddda93a5bd5d00a94945)
Signed-off-by: Julien Cristau <jcristau@debian.org>
---
xkb/xkb.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
diff --git a/xkb/xkb.c b/xkb/xkb.c
index dc570f0..6fc938b 100644
--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -4961,14 +4961,13 @@ static char *
_GetCountedString(char **wire_inout, Bool swap)
{
char *wire, *str;
- CARD16 len, *plen;
+ CARD16 len;
wire = *wire_inout;
- plen = (CARD16 *) wire;
+ len = *(CARD16 *) wire;
if (swap) {
- swaps(plen);
+ swaps(&len);
}
- len = *plen;
str = malloc(len + 1);
if (str) {
memcpy(str, &wire[2], len);
@@ -4985,25 +4984,28 @@ _CheckSetDoodad(char **wire_inout,
{
char *wire;
xkbDoodadWireDesc *dWire;
+ xkbAnyDoodadWireDesc any;
+ xkbTextDoodadWireDesc text;
XkbDoodadPtr doodad;
dWire = (xkbDoodadWireDesc *) (*wire_inout);
+ any = dWire->any;
wire = (char *) &dWire[1];
if (client->swapped) {
- swapl(&dWire->any.name);
- swaps(&dWire->any.top);
- swaps(&dWire->any.left);
- swaps(&dWire->any.angle);
+ swapl(&any.name);
+ swaps(&any.top);
+ swaps(&any.left);
+ swaps(&any.angle);
}
CHK_ATOM_ONLY(dWire->any.name);
- doodad = XkbAddGeomDoodad(geom, section, dWire->any.name);
+ doodad = XkbAddGeomDoodad(geom, section, any.name);
if (!doodad)
return BadAlloc;
doodad->any.priority = dWire->any.priority;
switch (doodad->any.type) {
case XkbOutlineDoodad:
case XkbSolidDoodad:
@@ -5026,12 +5028,13 @@ _CheckSetDoodad(char **wire_inout,
dWire->text.colorNdx);
return BadMatch;
}
+ text = dWire->text;
if (client->swapped) {
- swaps(&dWire->text.width);
- swaps(&dWire->text.height);
+ swaps(&text.width);
+ swaps(&text.height);
}
- doodad->text.width = dWire->text.width;
- doodad->text.height = dWire->text.height;
+ doodad->text.width = text.width;
+ doodad->text.height = text.height;
doodad->text.color_ndx = dWire->text.colorNdx;
doodad->text.text = _GetCountedString(&wire, client->swapped);
doodad->text.font = _GetCountedString(&wire, client->swapped);
--
1.7.9.2
From 8f61533b16635a0a13f4048235246edb138fa40b Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Fri, 16 Jan 2015 08:44:45 +0100
Subject: [PATCH 2/2] xkb: Check strings length against request size
Ensure that the given strings length in an XkbSetGeometry request remain
within the limits of the size of the request.
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit 20079c36cf7d377938ca5478447d8b9045cb7d43)
(cherry picked from commit f160e722672dbb2b5215870b47bcc51461d96ff1)
Signed-off-by: Julien Cristau <jcristau@debian.org>
---
xkb/xkb.c | 65 +++++++++++++++++++++++++++++++++++++------------------------
1 file changed, 40 insertions(+), 25 deletions(-)
diff --git a/xkb/xkb.c b/xkb/xkb.c
index 6fc938b..c8a9e9e 100644
--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -4957,25 +4957,29 @@ ProcXkbGetGeometry(ClientPtr client)
/***====================================================================***/
-static char *
-_GetCountedString(char **wire_inout, Bool swap)
+static Status
+_GetCountedString(char **wire_inout, ClientPtr client, char **str)
{
- char *wire, *str;
+ char *wire, *next;
CARD16 len;
wire = *wire_inout;
len = *(CARD16 *) wire;
- if (swap) {
+ if (client->swapped) {
swaps(&len);
}
- str = malloc(len + 1);
- if (str) {
- memcpy(str, &wire[2], len);
- str[len] = '\0';
- }
- wire += XkbPaddedSize(len + 2);
- *wire_inout = wire;
- return str;
+ next = wire + XkbPaddedSize(len + 2);
+ /* Check we're still within the size of the request */
+ if (client->req_len <
+ bytes_to_int32(next - (char *) client->requestBuffer))
+ return BadValue;
+ *str = malloc(len + 1);
+ if (!*str)
+ return BadAlloc;
+ memcpy(*str, &wire[2], len);
+ *(*str + len) = '\0';
+ *wire_inout = next;
+ return Success;
}
static Status
@@ -4987,6 +4991,7 @@ _CheckSetDoodad(char **wire_inout,
xkbAnyDoodadWireDesc any;
xkbTextDoodadWireDesc text;
XkbDoodadPtr doodad;
+ Status status;
dWire = (xkbDoodadWireDesc *) (*wire_inout);
any = dWire->any;
@@ -5036,8 +5041,14 @@ _CheckSetDoodad(char **wire_inout,
doodad->text.width = text.width;
doodad->text.height = text.height;
doodad->text.color_ndx = dWire->text.colorNdx;
- doodad->text.text = _GetCountedString(&wire, client->swapped);
- doodad->text.font = _GetCountedString(&wire, client->swapped);
+ status = _GetCountedString(&wire, client, &doodad->text.text);
+ if (status != Success)
+ return status;
+ status = _GetCountedString(&wire, client, &doodad->text.font);
+ if (status != Success) {
+ free (doodad->text.text);
+ return status;
+ }
break;
case XkbIndicatorDoodad:
if (dWire->indicator.onColorNdx >= geom->num_colors) {
@@ -5072,7 +5083,9 @@ _CheckSetDoodad(char **wire_inout,
}
doodad->logo.color_ndx = dWire->logo.colorNdx;
doodad->logo.shape_ndx = dWire->logo.shapeNdx;
- doodad->logo.logo_name = _GetCountedString(&wire, client->swapped);
+ status = _GetCountedString(&wire, client, &doodad->logo.logo_name);
+ if (status != Success)
+ return status;
break;
default:
client->errorValue = _XkbErrCode2(0x4F, dWire->any.type);
@@ -5304,18 +5317,20 @@ _CheckSetGeom(XkbGeometryPtr geom, xkbSetGeometryReq * req, ClientPtr client)
char *wire;
wire = (char *) &req[1];
- geom->label_font = _GetCountedString(&wire, client->swapped);
+ status = _GetCountedString(&wire, client, &geom->label_font);
+ if (status != Success)
+ return status;
for (i = 0; i < req->nProperties; i++) {
char *name, *val;
- name = _GetCountedString(&wire, client->swapped);
- if (!name)
- return BadAlloc;
- val = _GetCountedString(&wire, client->swapped);
- if (!val) {
+ status = _GetCountedString(&wire, client, &name);
+ if (status != Success)
+ return status;
+ status = _GetCountedString(&wire, client, &val);
+ if (status != Success) {
free(name);
- return BadAlloc;
+ return status;
}
if (XkbAddGeomProperty(geom, name, val) == NULL) {
free(name);
@@ -5349,9 +5364,9 @@ _CheckSetGeom(XkbGeometryPtr geom, xkbSetGeometryReq * req, ClientPtr client)
for (i = 0; i < req->nColors; i++) {
char *name;
- name = _GetCountedString(&wire, client->swapped);
- if (!name)
- return BadAlloc;
+ status = _GetCountedString(&wire, client, &name);
+ if (status != Success)
+ return status;
if (!XkbAddGeomColor(geom, name, geom->num_colors)) {
free(name);
return BadAlloc;
--
1.7.9.2