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74 lines
2.4 KiB
Diff
74 lines
2.4 KiB
Diff
From 2351c83a77a478b49cba6beb2ad386835e264744 Mon Sep 17 00:00:00 2001
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From: Alan Coopersmith <alan.coopersmith@oracle.com>
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Date: Fri, 6 Mar 2015 22:54:58 -0800
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Subject: bdfReadCharacters: ensure metrics fit into xCharInfo struct
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[CVE-2015-1804]
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We use 32-bit ints to read from the bdf file, but then try to stick
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into a 16-bit int in the xCharInfo struct, so make sure they won't
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overflow that range.
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Found by afl-1.24b.
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v2: Verify that additions won't overflow 32-bit int range either.
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v3: As Julien correctly observes, the previous check for bh & bw not
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being < 0 reduces the number of cases we need to check for overflow.
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Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
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Reviewed-by: Julien Cristau <jcristau@debian.org>
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diff --git a/src/bitmap/bdfread.c b/src/bitmap/bdfread.c
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index 1b29b81..a0ace8f 100644
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--- a/src/bitmap/bdfread.c
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+++ b/src/bitmap/bdfread.c
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@@ -62,8 +62,16 @@ from The Open Group.
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#if HAVE_STDINT_H
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#include <stdint.h>
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-#elif !defined(INT32_MAX)
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-#define INT32_MAX 0x7fffffff
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+#else
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+# ifndef INT32_MAX
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+# define INT32_MAX 0x7fffffff
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+# endif
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+# ifndef INT16_MAX
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+# define INT16_MAX 0x7fff
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+# endif
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+# ifndef INT16_MIN
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+# define INT16_MIN (0 - 0x8000)
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+# endif
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#endif
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#define INDICES 256
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@@ -417,6 +425,12 @@ bdfReadCharacters(FontFilePtr file, FontPtr pFont, bdfFileState *pState,
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bdfError("DWIDTH y value must be zero\n");
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goto BAILOUT;
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}
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+ /* xCharInfo metrics are stored as INT16 */
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+ if ((wx < 0) || (wx > INT16_MAX)) {
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+ bdfError("character '%s' has out of range width, %d\n",
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+ charName, wx);
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+ goto BAILOUT;
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+ }
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line = bdfGetLine(file, lineBuf, BDFLINELEN);
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if ((!line) || (sscanf((char *) line, "BBX %d %d %d %d", &bw, &bh, &bl, &bb) != 4)) {
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bdfError("bad 'BBX'\n");
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@@ -427,6 +441,14 @@ bdfReadCharacters(FontFilePtr file, FontPtr pFont, bdfFileState *pState,
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charName, bw, bh);
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goto BAILOUT;
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}
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+ /* xCharInfo metrics are read as int, but stored as INT16 */
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+ if ((bl > INT16_MAX) || (bl < INT16_MIN) ||
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+ (bb > INT16_MAX) || (bb < INT16_MIN) ||
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+ (bw > (INT16_MAX - bl)) || (bh > (INT16_MAX - bb))) {
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+ bdfError("character '%s' has out of range metrics, %d %d %d %d\n",
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+ charName, bl, (bl+bw), (bh+bb), -bb);
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+ goto BAILOUT;
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+ }
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line = bdfGetLine(file, lineBuf, BDFLINELEN);
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if ((line) && (bdfIsPrefix(line, "ATTRIBUTES"))) {
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for (p = line + strlen("ATTRIBUTES ");
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--
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cgit v0.10.2
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