[OE-core] [PATCH 13/15] squashfs: fix CVE-2012-4025
Scott Garman
scott.a.garman at intel.com
Fri Dec 28 21:41:46 UTC 2012
From: "yanjun.zhu" <yanjun.zhu at windriver.com>
CQID:WIND00366813
Reference: http://squashfs.git.sourceforge.net/git/gitweb.cgi?
p=squashfs/squashfs;a=patch;h=8515b3d420f502c5c0236b86e2d6d7e3b23c190e
Integer overflow in the queue_init function in unsquashfs.c in
unsquashfs in Squashfs 4.2 and earlier allows remote attackers
to execute arbitrary code via a crafted block_log field in the
superblock of a .sqsh file, leading to a heap-based buffer overflow.
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2012-4025
Signed-off-by: yanjun.zhu <yanjun.zhu at windriver.com>
[YOCTO #3564]
Signed-off-by: Saul Wold <sgw at linux.intel.com>
---
.../patches/squashfs-4.2-fix-CVE-2012-4025.patch | 190 +++++++++++++++++
...dd-a-commment-and-fix-some-other-comments.patch | 38 ++++
.../patches/squashfs-fix-open-file-limit.patch | 215 ++++++++++++++++++++
.../squashfs-tools/squashfs-tools_4.2.bb | 5 +-
4 files changed, 447 insertions(+), 1 deletion(-)
create mode 100644 meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4025.patch
create mode 100644 meta/recipes-devtools/squashfs-tools/patches/squashfs-add-a-commment-and-fix-some-other-comments.patch
create mode 100644 meta/recipes-devtools/squashfs-tools/patches/squashfs-fix-open-file-limit.patch
diff --git a/meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4025.patch b/meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4025.patch
new file mode 100644
index 0000000..0dabfba
--- /dev/null
+++ b/meta/recipes-devtools/squashfs-tools/patches/squashfs-4.2-fix-CVE-2012-4025.patch
@@ -0,0 +1,190 @@
+Upstream-Status: Backport
+
+Reference: http://squashfs.git.sourceforge.net/git/gitweb.cgi?
+p=squashfs/squashfs;a=patch;h=8515b3d420f502c5c0236b86e2d6d7e3b23c190e
+
+Integer overflow in the queue_init function in unsquashfs.c in
+unsquashfs in Squashfs 4.2 and earlier allows remote attackers
+to execute arbitrary code via a crafted block_log field in the
+superblock of a .sqsh file, leading to a heap-based buffer overflow.
+
+http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2012-4025
+
+Signed-off-by: yanjun.zhu <yanjun.zhu at windriver.com>
+
+--- a/unsquashfs.c 2012-11-30 17:57:57.000000000 +0800
++++ b/unsquashfs.c 2012-11-30 17:58:09.000000000 +0800
+@@ -33,6 +33,7 @@
+ #include <sys/types.h>
+ #include <sys/time.h>
+ #include <sys/resource.h>
++#include <limits.h>
+
+ struct cache *fragment_cache, *data_cache;
+ struct queue *to_reader, *to_deflate, *to_writer, *from_writer;
+@@ -138,6 +139,24 @@ void sigalrm_handler()
+ }
+
+
++int add_overflow(int a, int b)
++{
++ return (INT_MAX - a) < b;
++}
++
++
++int shift_overflow(int a, int shift)
++{
++ return (INT_MAX >> shift) < a;
++}
++
++
++int multiply_overflow(int a, int multiplier)
++{
++ return (INT_MAX / multiplier) < a;
++}
++
++
+ struct queue *queue_init(int size)
+ {
+ struct queue *queue = malloc(sizeof(struct queue));
+@@ -145,6 +164,10 @@ struct queue *queue_init(int size)
+ if(queue == NULL)
+ EXIT_UNSQUASH("Out of memory in queue_init\n");
+
++ if(add_overflow(size, 1) ||
++ multiply_overflow(size + 1, sizeof(void *)))
++ EXIT_UNSQUASH("Size too large in queue_init\n");
++
+ queue->data = malloc(sizeof(void *) * (size + 1));
+ if(queue->data == NULL)
+ EXIT_UNSQUASH("Out of memory in queue_init\n");
+@@ -1948,13 +1971,30 @@ void initialise_threads(int fragment_buf
+ * allocate to_reader, to_deflate and to_writer queues. Set based on
+ * open file limit and cache size, unless open file limit is unlimited,
+ * in which case set purely based on cache limits
++ *
++ * In doing so, check that the user supplied values do not overflow
++ * a signed int
+ */
+ if (max_files != -1) {
++ if(add_overflow(data_buffer_size, max_files) ||
++ add_overflow(data_buffer_size, max_files * 2))
++ EXIT_UNSQUASH("Data queue size is too large\n");
++
+ to_reader = queue_init(max_files + data_buffer_size);
+ to_deflate = queue_init(max_files + data_buffer_size);
+ to_writer = queue_init(max_files * 2 + data_buffer_size);
+ } else {
+- int all_buffers_size = fragment_buffer_size + data_buffer_size;
++ int all_buffers_size;
++
++ if(add_overflow(fragment_buffer_size, data_buffer_size))
++ EXIT_UNSQUASH("Data and fragment queues combined are"
++ " too large\n");
++
++ all_buffers_size = fragment_buffer_size + data_buffer_size;
++
++ if(add_overflow(all_buffers_size, all_buffers_size))
++ EXIT_UNSQUASH("Data and fragment queues combined are"
++ " too large\n");
+
+ to_reader = queue_init(all_buffers_size);
+ to_deflate = queue_init(all_buffers_size);
+@@ -2059,6 +2099,32 @@ void progress_bar(long long current, lon
+ }
+
+
++int parse_number(char *arg, int *res)
++{
++ char *b;
++ long number = strtol(arg, &b, 10);
++
++ /* check for trailing junk after number */
++ if(*b != '\0')
++ return 0;
++
++ /* check for strtol underflow or overflow in conversion */
++ if(number == LONG_MIN || number == LONG_MAX)
++ return 0;
++
++ /* reject negative numbers as invalid */
++ if(number < 0)
++ return 0;
++
++ /* check if long result will overflow signed int */
++ if(number > INT_MAX)
++ return 0;
++
++ *res = number;
++ return 1;
++}
++
++
+ #define VERSION() \
+ printf("unsquashfs version 4.2 (2011/02/28)\n");\
+ printf("copyright (C) 2011 Phillip Lougher "\
+@@ -2140,8 +2206,8 @@ int main(int argc, char *argv[])
+ } else if(strcmp(argv[i], "-data-queue") == 0 ||
+ strcmp(argv[i], "-da") == 0) {
+ if((++i == argc) ||
+- (data_buffer_size = strtol(argv[i], &b,
+- 10), *b != '\0')) {
++ !parse_number(argv[i],
++ &data_buffer_size)) {
+ ERROR("%s: -data-queue missing or invalid "
+ "queue size\n", argv[0]);
+ exit(1);
+@@ -2154,8 +2220,8 @@ int main(int argc, char *argv[])
+ } else if(strcmp(argv[i], "-frag-queue") == 0 ||
+ strcmp(argv[i], "-fr") == 0) {
+ if((++i == argc) ||
+- (fragment_buffer_size = strtol(argv[i],
+- &b, 10), *b != '\0')) {
++ !parse_number(argv[i],
++ &fragment_buffer_size)) {
+ ERROR("%s: -frag-queue missing or invalid "
+ "queue size\n", argv[0]);
+ exit(1);
+@@ -2280,11 +2346,39 @@ options:
+ block_log = sBlk.s.block_log;
+
+ /*
++ * Sanity check block size and block log.
++ *
++ * Check they're within correct limits
++ */
++ if(block_size > SQUASHFS_FILE_MAX_SIZE ||
++ block_log > SQUASHFS_FILE_MAX_LOG)
++ EXIT_UNSQUASH("Block size or block_log too large."
++ " File system is corrupt.\n");
++
++ /*
++ * Check block_size and block_log match
++ */
++ if(block_size != (1 << block_log))
++ EXIT_UNSQUASH("Block size and block_log do not match."
++ " File system is corrupt.\n");
++
++ /*
+ * convert from queue size in Mbytes to queue size in
+- * blocks
++ * blocks.
++ *
++ * In doing so, check that the user supplied values do not
++ * overflow a signed int
+ */
+- fragment_buffer_size <<= 20 - block_log;
+- data_buffer_size <<= 20 - block_log;
++ if(shift_overflow(fragment_buffer_size, 20 - block_log))
++ EXIT_UNSQUASH("Fragment queue size is too large\n");
++ else
++ fragment_buffer_size <<= 20 - block_log;
++
++ if(shift_overflow(data_buffer_size, 20 - block_log))
++ EXIT_UNSQUASH("Data queue size is too large\n");
++ else
++ data_buffer_size <<= 20 - block_log;
++
+ initialise_threads(fragment_buffer_size, data_buffer_size);
+
+ fragment_data = malloc(block_size);
diff --git a/meta/recipes-devtools/squashfs-tools/patches/squashfs-add-a-commment-and-fix-some-other-comments.patch b/meta/recipes-devtools/squashfs-tools/patches/squashfs-add-a-commment-and-fix-some-other-comments.patch
new file mode 100644
index 0000000..fa075f9
--- /dev/null
+++ b/meta/recipes-devtools/squashfs-tools/patches/squashfs-add-a-commment-and-fix-some-other-comments.patch
@@ -0,0 +1,38 @@
+Upstream-Status: Backport
+
+unsquashfs: add a commment and fix some other comments
+
+Signed-off-by: yanjun.zhu <yanjun.zhu at windriver.com>
+
+diff -urpN a/unsquashfs.c b/unsquashfs.c
+--- a/unsquashfs.c 2012-11-30 15:27:14.000000000 +0800
++++ b/unsquashfs.c 2012-11-30 15:27:56.000000000 +0800
+@@ -814,7 +814,7 @@ int write_file(struct inode *inode, char
+
+ /*
+ * the writer thread is queued a squashfs_file structure describing the
+- * file. If the file has one or more blocks or a fragments they are
++ * file. If the file has one or more blocks or a fragment they are
+ * queued separately (references to blocks in the cache).
+ */
+ file->fd = file_fd;
+@@ -838,7 +838,7 @@ int write_file(struct inode *inode, char
+ block->offset = 0;
+ block->size = i == file_end ? inode->data & (block_size - 1) :
+ block_size;
+- if(block_list[i] == 0) /* sparse file */
++ if(block_list[i] == 0) /* sparse block */
+ block->buffer = NULL;
+ else {
+ block->buffer = cache_get(data_cache, start,
+@@ -2161,6 +2161,10 @@ options:
+ block_size = sBlk.s.block_size;
+ block_log = sBlk.s.block_log;
+
++ /*
++ * convert from queue size in Mbytes to queue size in
++ * blocks
++ */
+ fragment_buffer_size <<= 20 - block_log;
+ data_buffer_size <<= 20 - block_log;
+ initialise_threads(fragment_buffer_size, data_buffer_size);
diff --git a/meta/recipes-devtools/squashfs-tools/patches/squashfs-fix-open-file-limit.patch b/meta/recipes-devtools/squashfs-tools/patches/squashfs-fix-open-file-limit.patch
new file mode 100644
index 0000000..c60f7b4
--- /dev/null
+++ b/meta/recipes-devtools/squashfs-tools/patches/squashfs-fix-open-file-limit.patch
@@ -0,0 +1,215 @@
+Upstream-Status: Backport
+
+unsquashfs: fix open file limit
+
+Previously Unsquashfs relied on the to_writer queue being
+set to 1000 to limit the amount of open file read-ahead to a
+maximum of 500. For the default process limit of 1024 open files
+this was perhaps acceptable, but it obviously breaks if ulimit has
+been used to set the open file limit to below 504 (this includes
+stdin, stdout, stderr and the Squashfs filesystem being unsquashed).
+
+More importantly setting the to_writer queue to 1000 to limit
+the amount of files open has always been an inherent performance
+hit because the to_writer queue queues blocks. It limits the
+block readhead to 1000 blocks, irrespective of how many files
+that represents. A single file containing more than 1000 blocks
+will still be limited to a 1000 block readahead even though the
+data block cache typically can buffer more than this (at the
+default data cache size of 256 Mbytes and the default block size
+of 128 Kbytes, it can buffer 2048 blocks). Obviously the
+caches serve more than just a read-ahead role (they also
+cache decompressed blocks in case they're referenced later e.g.
+by duplicate files), but the artificial limit imposed on
+the read-ahead due to setting the to_writer queue to 1000 is
+unnecessary.
+
+This commit does away with the need to limit the to_writer queue,
+by introducing open_wait() and close_wake() calls which correctly
+track the amount of open files.
+
+Signed-off-by: Phillip Lougher <phillip at squashfs.org.uk>
+
+Signed-off-by: yanjun.zhu <yanjun.zhu at windriver.com>
+
+diff -urpN a/unsquashfs.c b/unsquashfs.c
+--- a/unsquashfs.c 2012-11-30 15:31:29.000000000 +0800
++++ b/unsquashfs.c 2012-11-30 15:32:03.000000000 +0800
+@@ -31,6 +31,8 @@
+
+ #include <sys/sysinfo.h>
+ #include <sys/types.h>
++#include <sys/time.h>
++#include <sys/resource.h>
+
+ struct cache *fragment_cache, *data_cache;
+ struct queue *to_reader, *to_deflate, *to_writer, *from_writer;
+@@ -784,6 +786,46 @@ failure:
+ }
+
+
++pthread_mutex_t open_mutex = PTHREAD_MUTEX_INITIALIZER;
++pthread_cond_t open_empty = PTHREAD_COND_INITIALIZER;
++int open_unlimited, open_count;
++#define OPEN_FILE_MARGIN 10
++
++
++void open_init(int count)
++{
++ open_count = count;
++ open_unlimited = count == -1;
++}
++
++
++int open_wait(char *pathname, int flags, mode_t mode)
++{
++ if (!open_unlimited) {
++ pthread_mutex_lock(&open_mutex);
++ while (open_count == 0)
++ pthread_cond_wait(&open_empty, &open_mutex);
++ open_count --;
++ pthread_mutex_unlock(&open_mutex);
++ }
++
++ return open(pathname, flags, mode);
++}
++
++
++void close_wake(int fd)
++{
++ close(fd);
++
++ if (!open_unlimited) {
++ pthread_mutex_lock(&open_mutex);
++ open_count ++;
++ pthread_cond_signal(&open_empty);
++ pthread_mutex_unlock(&open_mutex);
++ }
++}
++
++
+ int write_file(struct inode *inode, char *pathname)
+ {
+ unsigned int file_fd, i;
+@@ -794,8 +836,8 @@ int write_file(struct inode *inode, char
+
+ TRACE("write_file: regular file, blocks %d\n", inode->blocks);
+
+- file_fd = open(pathname, O_CREAT | O_WRONLY | (force ? O_TRUNC : 0),
+- (mode_t) inode->mode & 0777);
++ file_fd = open_wait(pathname, O_CREAT | O_WRONLY |
++ (force ? O_TRUNC : 0), (mode_t) inode->mode & 0777);
+ if(file_fd == -1) {
+ ERROR("write_file: failed to create file %s, because %s\n",
+ pathname, strerror(errno));
+@@ -1712,7 +1754,7 @@ void *writer(void *arg)
+ }
+ }
+
+- close(file_fd);
++ close_wake(file_fd);
+ if(failed == FALSE)
+ set_attributes(file->pathname, file->mode, file->uid,
+ file->gid, file->time, file->xattr, force);
+@@ -1803,9 +1845,9 @@ void *progress_thread(void *arg)
+
+ void initialise_threads(int fragment_buffer_size, int data_buffer_size)
+ {
+- int i;
++ struct rlimit rlim;
++ int i, max_files, res;
+ sigset_t sigmask, old_mask;
+- int all_buffers_size = fragment_buffer_size + data_buffer_size;
+
+ sigemptyset(&sigmask);
+ sigaddset(&sigmask, SIGINT);
+@@ -1841,10 +1883,86 @@ void initialise_threads(int fragment_buf
+ EXIT_UNSQUASH("Out of memory allocating thread descriptors\n");
+ deflator_thread = &thread[3];
+
+- to_reader = queue_init(all_buffers_size);
+- to_deflate = queue_init(all_buffers_size);
+- to_writer = queue_init(1000);
++ /*
++ * dimensioning the to_reader and to_deflate queues. The size of
++ * these queues is directly related to the amount of block
++ * read-ahead possible. To_reader queues block read requests to
++ * the reader thread and to_deflate queues block decompression
++ * requests to the deflate thread(s) (once the block has been read by
++ * the reader thread). The amount of read-ahead is determined by
++ * the combined size of the data_block and fragment caches which
++ * determine the total number of blocks which can be "in flight"
++ * at any one time (either being read or being decompressed)
++ *
++ * The maximum file open limit, however, affects the read-ahead
++ * possible, in that for normal sizes of the fragment and data block
++ * caches, where the incoming files have few data blocks or one fragment
++ * only, the file open limit is likely to be reached before the
++ * caches are full. This means the worst case sizing of the combined
++ * sizes of the caches is unlikely to ever be necessary. However, is is
++ * obvious read-ahead up to the data block cache size is always possible
++ * irrespective of the file open limit, because a single file could
++ * contain that number of blocks.
++ *
++ * Choosing the size as "file open limit + data block cache size" seems
++ * to be a reasonable estimate. We can reasonably assume the maximum
++ * likely read-ahead possible is data block cache size + one fragment
++ * per open file.
++ *
++ * dimensioning the to_writer queue. The size of this queue is
++ * directly related to the amount of block read-ahead possible.
++ * However, unlike the to_reader and to_deflate queues, this is
++ * complicated by the fact the to_writer queue not only contains
++ * entries for fragments and data_blocks but it also contains
++ * file entries, one per open file in the read-ahead.
++ *
++ * Choosing the size as "2 * (file open limit) +
++ * data block cache size" seems to be a reasonable estimate.
++ * We can reasonably assume the maximum likely read-ahead possible
++ * is data block cache size + one fragment per open file, and then
++ * we will have a file_entry for each open file.
++ */
++ res = getrlimit(RLIMIT_NOFILE, &rlim);
++ if (res == -1) {
++ ERROR("failed to get open file limit! Defaulting to 1\n");
++ rlim.rlim_cur = 1;
++ }
++
++ if (rlim.rlim_cur != RLIM_INFINITY) {
++ /*
++ * leave OPEN_FILE_MARGIN free (rlim_cur includes fds used by
++ * stdin, stdout, stderr and filesystem fd
++ */
++ if (rlim.rlim_cur <= OPEN_FILE_MARGIN)
++ /* no margin, use minimum possible */
++ max_files = 1;
++ else
++ max_files = rlim.rlim_cur - OPEN_FILE_MARGIN;
++ } else
++ max_files = -1;
++
++ /* set amount of available files for use by open_wait and close_wake */
++ open_init(max_files);
++
++ /*
++ * allocate to_reader, to_deflate and to_writer queues. Set based on
++ * open file limit and cache size, unless open file limit is unlimited,
++ * in which case set purely based on cache limits
++ */
++ if (max_files != -1) {
++ to_reader = queue_init(max_files + data_buffer_size);
++ to_deflate = queue_init(max_files + data_buffer_size);
++ to_writer = queue_init(max_files * 2 + data_buffer_size);
++ } else {
++ int all_buffers_size = fragment_buffer_size + data_buffer_size;
++
++ to_reader = queue_init(all_buffers_size);
++ to_deflate = queue_init(all_buffers_size);
++ to_writer = queue_init(all_buffers_size * 2);
++ }
++
+ from_writer = queue_init(1);
++
+ fragment_cache = cache_init(block_size, fragment_buffer_size);
+ data_cache = cache_init(block_size, data_buffer_size);
+ pthread_create(&thread[0], NULL, reader, NULL);
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 9922f1e..528efed 100644
--- a/meta/recipes-devtools/squashfs-tools/squashfs-tools_4.2.bb
+++ b/meta/recipes-devtools/squashfs-tools/squashfs-tools_4.2.bb
@@ -8,12 +8,15 @@ LIC_FILES_CHKSUM = "file://../COPYING;md5=0636e73ff0215e8d672dc4c32c317bb3 \
file://../../7zC.txt;beginline=12;endline=16;md5=2056cd6d919ebc3807602143c7449a7c \
"
DEPENDS = "attr zlib xz"
-PR = "1"
+PR = "r2"
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 \
+ file://squashfs-add-a-commment-and-fix-some-other-comments.patch \
+ file://squashfs-fix-open-file-limit.patch \
+ file://squashfs-4.2-fix-CVE-2012-4025.patch \
"
SRC_URI[squashfs.md5sum] = "1b7a781fb4cf8938842279bd3e8ee852"
SRC_URI[squashfs.sha256sum] = "d9e0195aa922dbb665ed322b9aaa96e04a476ee650f39bbeadb0d00b24022e96"
--
1.7.9.5
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