Re: [oe][PATCH 1/1] squashfs: fix for CVE-2012-4024

[Saul Wold <sgw@linux.intel.com>]

On 11/29/2012 01:14 AM, yanjun.zhu wrote:
> From: "yanjun.zhu" <yanjun.zhu@windriver.com>
>
> Reference:http://squashfs.git.sourceforge.net/git/gitweb.cgi?p=
> squashfs/squashfs;a=commit;h=19c38fba0be1ce949ab44310d7f49887576cc123
>
> Fix potential stack overflow in get_component() where an individual
> pathname component in an extract file (specified on the command line
> or in an extract file) could exceed the 1024 byte sized targname
> allocated on the stack.
>
> Fix by dynamically allocating targname rather than storing it as
> a fixed size on the stack.
>
> [YOCTO #3513]
>
> Signed-off-by: yanjun.zhu <yanjun.zhu@windriver.com>
> ---
>   .../patches/squashfs-4.2-fix-CVE-2012-4024.patch   | 58 ++++++++++++++++++++++
>   .../squashfs-tools/squashfs-tools_4.2.bb           |  3 ++
>   2 files changed, 61 insertions(+)
>   create mode 100644 meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4024.patch
>
> diff --git a/meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4024.patch b/meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4024.patch
> new file mode 100644
> index 0000000..10f6bb2
> --- /dev/null
> +++ b/meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4024.patch

Thank you for your work on the the CVE updates, please make sure you 
also let the Danny Stable maintainer know if these are for Danny also.

You also need to add Signed-off-by and Upstream-Status to the patch.

Thanks
	Sau!

> @@ -0,0 +1,58 @@
> +diff -urpN a/unsquashfs.c b/unsquashfs.c
> +--- a/unsquashfs.c	2012-11-29 17:04:08.000000000 +0800
> ++++ b/unsquashfs.c	2012-11-29 17:04:25.000000000 +0800
> +@@ -1034,15 +1034,18 @@ void squashfs_closedir(struct dir *dir)
> + }
> +
> +
> +-char *get_component(char *target, char *targname)
> ++char *get_component(char *target, char **targname)
> + {
> ++	char *start;
> ++
> + 	while(*target == '/')
> + 		target ++;
> +
> ++	start = target;
> + 	while(*target != '/' && *target!= '\0')
> +-		*targname ++ = *target ++;
> ++		target ++;
> +
> +-	*targname = '\0';
> ++	*targname = strndup(start, target - start);
> +
> + 	return target;
> + }
> +@@ -1068,12 +1071,12 @@ void free_path(struct pathname *paths)
> +
> + struct pathname *add_path(struct pathname *paths, char *target, char *alltarget)
> + {
> +-	char targname[1024];
> ++	char *targname;
> + 	int i, error;
> +
> + 	TRACE("add_path: adding \"%s\" extract file\n", target);
> +
> +-	target = get_component(target, targname);
> ++	target = get_component(target, &targname);
> +
> + 	if(paths == NULL) {
> + 		paths = malloc(sizeof(struct pathname));
> +@@ -1097,7 +1100,7 @@ struct pathname *add_path(struct pathnam
> + 			sizeof(struct path_entry));
> + 		if(paths->name == NULL)
> + 			EXIT_UNSQUASH("Out of memory in add_path\n");	
> +-		paths->name[i].name = strdup(targname);
> ++		paths->name[i].name = targname;
> + 		paths->name[i].paths = NULL;
> + 		if(use_regex) {
> + 			paths->name[i].preg = malloc(sizeof(regex_t));
> +@@ -1130,6 +1133,8 @@ struct pathname *add_path(struct pathnam
> + 		/*
> + 		 * existing matching entry
> + 		 */
> ++		free(targname);
> ++
> + 		if(paths->name[i].paths == NULL) {
> + 			/*
> + 			 * No sub-directory which means this is the leaf
> diff --git a/meta/recipes-devtools/squashfs-tools/squashfs-tools_4.2.bb b/meta/recipes-devtools/squashfs-tools/squashfs-tools_4.2.bb
> index c54081b..9922f1e 100644
> --- a/meta/recipes-devtools/squashfs-tools/squashfs-tools_4.2.bb
> +++ b/meta/recipes-devtools/squashfs-tools/squashfs-tools_4.2.bb
> @@ -3,6 +3,7 @@
>   DESCRIPTION = "Tools to manipulate Squashfs filesystems."
>   SECTION = "base"
>   LICENSE = "GPL-2 & PD"
> +FILESEXTRAPATHS_prepend := "${THISDIR}/patches:"
>   LIC_FILES_CHKSUM = "file://../COPYING;md5=0636e73ff0215e8d672dc4c32c317bb3 \
>                       file://../../7zC.txt;beginline=12;endline=16;md5=2056cd6d919ebc3807602143c7449a7c \
>                      "
> @@ -12,6 +13,8 @@ PR = "1"
>   SRC_URI = "${SOURCEFORGE_MIRROR}/squashfs/squashfs${PV}.tar.gz;name=squashfs \
>              http://downloads.sourceforge.net/sevenzip/lzma465.tar.bz2;name=lzma \
>             "
> +SRC_URI += "file://squashfs-4.2-fix-CVE-2012-4024.patch \
> +           "
>   SRC_URI[squashfs.md5sum] = "1b7a781fb4cf8938842279bd3e8ee852"
>   SRC_URI[squashfs.sha256sum] = "d9e0195aa922dbb665ed322b9aaa96e04a476ee650f39bbeadb0d00b24022e96"
>   SRC_URI[lzma.md5sum] = "29d5ffd03a5a3e51aef6a74e9eafb759"
>