152 lines
4.2 KiB
Diff
152 lines
4.2 KiB
Diff
From 52603840b1c5d923cc998335fb651a53d42a036c Mon Sep 17 00:00:00 2001
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From: Alan Coopersmith <alan.coopersmith@oracle.com>
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Date: Sat, 7 Jan 2023 12:44:28 -0800
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Subject: [PATCH libXpm 2/5] Fix CVE-2022-44617: Runaway loop with width of 0
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and enormous height
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When reading XPM images from a file with libXpm 3.5.14 or older, if a
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image has a width of 0 and a very large height, the ParsePixels() function
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will loop over the entire height calling getc() and ungetc() repeatedly,
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or in some circumstances, may loop seemingly forever, which may cause a
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denial of service to the calling program when given a small crafted XPM
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file to parse.
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Closes: #2
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Reported-by: Martin Ettl <ettl.martin78@googlemail.com>
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Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
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---
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src/data.c | 20 ++++++++++++++------
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src/parse.c | 31 +++++++++++++++++++++++++++----
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2 files changed, 41 insertions(+), 10 deletions(-)
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diff --git a/src/data.c b/src/data.c
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index bfad4ff..7524e65 100644
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--- a/src/data.c
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+++ b/src/data.c
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@@ -195,19 +195,23 @@ xpmNextString(xpmData *data)
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register char c;
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/* get to the end of the current string */
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- if (data->Eos)
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- while ((c = *data->cptr++) && c != data->Eos);
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+ if (data->Eos) {
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+ while ((c = *data->cptr++) && c != data->Eos && c != '\0');
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+
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+ if (c == '\0')
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+ return XpmFileInvalid;
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+ }
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/*
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* then get to the beginning of the next string looking for possible
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* comment
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*/
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if (data->Bos) {
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- while ((c = *data->cptr++) && c != data->Bos)
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+ while ((c = *data->cptr++) && c != data->Bos && c != '\0')
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if (data->Bcmt && c == data->Bcmt[0])
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ParseComment(data);
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} else if (data->Bcmt) { /* XPM2 natural */
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- while ((c = *data->cptr++) == data->Bcmt[0])
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+ while (((c = *data->cptr++) == data->Bcmt[0]) && c != '\0')
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ParseComment(data);
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data->cptr--;
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}
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@@ -216,9 +220,13 @@ xpmNextString(xpmData *data)
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FILE *file = data->stream.file;
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/* get to the end of the current string */
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- if (data->Eos)
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+ if (data->Eos) {
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while ((c = Getc(data, file)) != data->Eos && c != EOF);
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+ if (c == EOF)
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+ return XpmFileInvalid;
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+ }
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+
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/*
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* then get to the beginning of the next string looking for possible
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* comment
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@@ -234,7 +242,7 @@ xpmNextString(xpmData *data)
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Ungetc(data, c, file);
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}
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}
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- return 0;
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+ return XpmSuccess;
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}
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diff --git a/src/parse.c b/src/parse.c
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index c19209c..e97d771 100644
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--- a/src/parse.c
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+++ b/src/parse.c
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@@ -391,6 +391,13 @@ ParsePixels(
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{
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unsigned int *iptr, *iptr2 = NULL; /* found by Egbert Eich */
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unsigned int a, x, y;
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+ int ErrorStatus;
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+
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+ if ((width == 0) && (height != 0))
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+ return (XpmFileInvalid);
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+
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+ if ((height == 0) && (width != 0))
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+ return (XpmFileInvalid);
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if ((height > 0 && width >= UINT_MAX / height) ||
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width * height >= UINT_MAX / sizeof(unsigned int))
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@@ -428,7 +435,11 @@ ParsePixels(
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colidx[(unsigned char)colorTable[a].string[0]] = a + 1;
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for (y = 0; y < height; y++) {
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- xpmNextString(data);
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+ ErrorStatus = xpmNextString(data);
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+ if (ErrorStatus != XpmSuccess) {
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+ XpmFree(iptr2);
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+ return (ErrorStatus);
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+ }
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for (x = 0; x < width; x++, iptr++) {
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int c = xpmGetC(data);
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@@ -475,7 +486,11 @@ do \
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}
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for (y = 0; y < height; y++) {
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- xpmNextString(data);
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+ ErrorStatus = xpmNextString(data);
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+ if (ErrorStatus != XpmSuccess) {
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+ XpmFree(iptr2);
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+ return (ErrorStatus);
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+ }
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for (x = 0; x < width; x++, iptr++) {
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int cc1 = xpmGetC(data);
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if (cc1 > 0 && cc1 < 256) {
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@@ -515,7 +530,11 @@ do \
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xpmHashAtom *slot;
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for (y = 0; y < height; y++) {
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- xpmNextString(data);
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+ ErrorStatus = xpmNextString(data);
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+ if (ErrorStatus != XpmSuccess) {
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+ XpmFree(iptr2);
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+ return (ErrorStatus);
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+ }
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for (x = 0; x < width; x++, iptr++) {
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for (a = 0, s = buf; a < cpp; a++, s++) {
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int c = xpmGetC(data);
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@@ -535,7 +554,11 @@ do \
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}
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} else {
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for (y = 0; y < height; y++) {
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- xpmNextString(data);
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+ ErrorStatus = xpmNextString(data);
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+ if (ErrorStatus != XpmSuccess) {
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+ XpmFree(iptr2);
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+ return (ErrorStatus);
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+ }
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for (x = 0; x < width; x++, iptr++) {
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for (a = 0, s = buf; a < cpp; a++, s++) {
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int c = xpmGetC(data);
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--
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2.39.0
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