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-rw-r--r--gnu/packages/patches/fontconfig-CVE-2016-5384.patch170
1 files changed, 0 insertions, 170 deletions
diff --git a/gnu/packages/patches/fontconfig-CVE-2016-5384.patch b/gnu/packages/patches/fontconfig-CVE-2016-5384.patch
deleted file mode 100644
index 617d5afbaf..0000000000
--- a/gnu/packages/patches/fontconfig-CVE-2016-5384.patch
+++ /dev/null
@@ -1,170 +0,0 @@
-Fix CVE-2016-5384 (double-free resulting in arbitrary code execution):
-
-<https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-5384>
-
-Copied from upstream code repository:
-
-<https://cgit.freedesktop.org/fontconfig/commit/?id=7a4a5bd7897d216f0794ca9dbce0a4a5c9d14940>
-
-From 7a4a5bd7897d216f0794ca9dbce0a4a5c9d14940 Mon Sep 17 00:00:00 2001
-From: Tobias Stoeckmann <tobias@stoeckmann.org>
-Date: Sat, 25 Jun 2016 19:18:53 +0200
-Subject: Properly validate offsets in cache files.
-
-The cache files are insufficiently validated. Even though the magic
-number at the beginning of the file as well as time stamps are checked,
-it is not verified if contained offsets are in legal ranges or are
-even pointers.
-
-The lack of validation allows an attacker to trigger arbitrary free()
-calls, which in turn allows double free attacks and therefore arbitrary
-code execution. Due to the conversion from offsets into pointers through
-macros, this even allows to circumvent ASLR protections.
-
-This attack vector allows privilege escalation when used with setuid
-binaries like fbterm. A user can create ~/.fonts or any other
-system-defined user-private font directory, run fc-cache and adjust
-cache files in ~/.cache/fontconfig. The execution of setuid binaries will
-scan these files and therefore are prone to attacks.
-
-If it's not about code execution, an endless loop can be created by
-letting linked lists become circular linked lists.
-
-This patch verifies that:
-
-- The file is not larger than the maximum addressable space, which
- basically only affects 32 bit systems. This allows out of boundary
- access into unallocated memory.
-- Offsets are always positive or zero
-- Offsets do not point outside file boundaries
-- No pointers are allowed in cache files, every "pointer or offset"
- field must be an offset or NULL
-- Iterating linked lists must not take longer than the amount of elements
- specified. A violation of this rule can break a possible endless loop.
-
-If one or more of these points are violated, the cache is recreated.
-This is current behaviour.
-
-Even though this patch fixes many issues, the use of mmap() shall be
-forbidden in setuid binaries. It is impossible to guarantee with these
-checks that a malicious user does not change cache files after
-verification. This should be handled in a different patch.
-
-Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
-
-diff --git a/src/fccache.c b/src/fccache.c
-index 71e8f03..02ec301 100644
---- a/src/fccache.c
-+++ b/src/fccache.c
-@@ -27,6 +27,7 @@
- #include <fcntl.h>
- #include <dirent.h>
- #include <string.h>
-+#include <limits.h>
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <assert.h>
-@@ -587,6 +588,82 @@ FcCacheTimeValid (FcConfig *config, FcCache *cache, struct stat *dir_stat)
- return cache->checksum == (int) dir_stat->st_mtime && fnano;
- }
-
-+static FcBool
-+FcCacheOffsetsValid (FcCache *cache)
-+{
-+ char *base = (char *)cache;
-+ char *end = base + cache->size;
-+ intptr_t *dirs;
-+ FcFontSet *fs;
-+ int i, j;
-+
-+ if (cache->dir < 0 || cache->dir > cache->size - sizeof (intptr_t) ||
-+ memchr (base + cache->dir, '\0', cache->size - cache->dir) == NULL)
-+ return FcFalse;
-+
-+ if (cache->dirs < 0 || cache->dirs >= cache->size ||
-+ cache->dirs_count < 0 ||
-+ cache->dirs_count > (cache->size - cache->dirs) / sizeof (intptr_t))
-+ return FcFalse;
-+
-+ dirs = FcCacheDirs (cache);
-+ if (dirs)
-+ {
-+ for (i = 0; i < cache->dirs_count; i++)
-+ {
-+ FcChar8 *dir;
-+
-+ if (dirs[i] < 0 ||
-+ dirs[i] > end - (char *) dirs - sizeof (intptr_t))
-+ return FcFalse;
-+
-+ dir = FcOffsetToPtr (dirs, dirs[i], FcChar8);
-+ if (memchr (dir, '\0', end - (char *) dir) == NULL)
-+ return FcFalse;
-+ }
-+ }
-+
-+ if (cache->set < 0 || cache->set > cache->size - sizeof (FcFontSet))
-+ return FcFalse;
-+
-+ fs = FcCacheSet (cache);
-+ if (fs)
-+ {
-+ if (fs->nfont > (end - (char *) fs) / sizeof (FcPattern))
-+ return FcFalse;
-+
-+ if (fs->fonts != 0 && !FcIsEncodedOffset(fs->fonts))
-+ return FcFalse;
-+
-+ for (i = 0; i < fs->nfont; i++)
-+ {
-+ FcPattern *font = FcFontSetFont (fs, i);
-+ FcPatternElt *e;
-+ FcValueListPtr l;
-+
-+ if ((char *) font < base ||
-+ (char *) font > end - sizeof (FcFontSet) ||
-+ font->elts_offset < 0 ||
-+ font->elts_offset > end - (char *) font ||
-+ font->num > (end - (char *) font - font->elts_offset) / sizeof (FcPatternElt))
-+ return FcFalse;
-+
-+
-+ e = FcPatternElts(font);
-+ if (e->values != 0 && !FcIsEncodedOffset(e->values))
-+ return FcFalse;
-+
-+ for (j = font->num, l = FcPatternEltValues(e); j >= 0 && l; j--, l = FcValueListNext(l))
-+ if (l->next != NULL && !FcIsEncodedOffset(l->next))
-+ break;
-+ if (j < 0)
-+ return FcFalse;
-+ }
-+ }
-+
-+ return FcTrue;
-+}
-+
- /*
- * Map a cache file into memory
- */
-@@ -596,7 +673,8 @@ FcDirCacheMapFd (FcConfig *config, int fd, struct stat *fd_stat, struct stat *di
- FcCache *cache;
- FcBool allocated = FcFalse;
-
-- if (fd_stat->st_size < (int) sizeof (FcCache))
-+ if (fd_stat->st_size > INTPTR_MAX ||
-+ fd_stat->st_size < (int) sizeof (FcCache))
- return NULL;
- cache = FcCacheFindByStat (fd_stat);
- if (cache)
-@@ -652,6 +730,7 @@ FcDirCacheMapFd (FcConfig *config, int fd, struct stat *fd_stat, struct stat *di
- if (cache->magic != FC_CACHE_MAGIC_MMAP ||
- cache->version < FC_CACHE_VERSION_NUMBER ||
- cache->size != (intptr_t) fd_stat->st_size ||
-+ !FcCacheOffsetsValid (cache) ||
- !FcCacheTimeValid (config, cache, dir_stat) ||
- !FcCacheInsert (cache, fd_stat))
- {
---
-cgit v0.10.2
-
generated by cgit v1.2.3 (git 2.45.2) at 2024-07-10 16:20:41 +0000