diff options
Diffstat (limited to 'main/squashfs-tools/0004-Unsquashfs-additional-write-outside-destination-dire.patch')
| -rw-r--r-- | main/squashfs-tools/0004-Unsquashfs-additional-write-outside-destination-dire.patch | 320 |
1 files changed, 0 insertions, 320 deletions
diff --git a/main/squashfs-tools/0004-Unsquashfs-additional-write-outside-destination-dire.patch b/main/squashfs-tools/0004-Unsquashfs-additional-write-outside-destination-dire.patch deleted file mode 100644 index 662fc62c0fd..00000000000 --- a/main/squashfs-tools/0004-Unsquashfs-additional-write-outside-destination-dire.patch +++ /dev/null @@ -1,320 +0,0 @@ -From 6bfefb7f73e183d1b6b4cd21a57d478f93e034ab Mon Sep 17 00:00:00 2001 -From: Phillip Lougher <phillip@squashfs.org.uk> -Date: Sun, 12 Sep 2021 23:50:06 +0100 -Subject: [PATCH 4/5] Unsquashfs: additional write outside destination - directory exploit fix - -An issue on github (https://github.com/plougher/squashfs-tools/issues/72) -showed how some specially crafted Squashfs filesystems containing -invalid file names (with '/' and '..') can cause Unsquashfs to write -files outside of the destination directory. - -Since then it has been shown that specially crafted Squashfs filesystems -that contain a symbolic link pointing outside of the destination directory, -coupled with an identically named file within the same directory, can -cause Unsquashfs to write files outside of the destination directory. - -Specifically the symbolic link produces a pathname pointing outside -of the destination directory, which is then followed when writing the -duplicate identically named file within the directory. - -This commit fixes this exploit by explictly checking for duplicate -filenames within a directory. As directories in v2.1, v3.x, and v4.0 -filesystems are sorted, this is achieved by checking for consecutively -identical filenames. Additionally directories are checked to -ensure they are sorted, to avoid attempts to evade the duplicate -check. - -Version 1.x and 2.0 filesystems (where the directories were unsorted) -are sorted and then the above duplicate filename check is applied. - -Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> ---- - squashfs-tools/Makefile | 6 +- - squashfs-tools/unsquash-1.c | 6 ++ - squashfs-tools/unsquash-12.c | 110 +++++++++++++++++++++++++++++++++ - squashfs-tools/unsquash-1234.c | 21 +++++++ - squashfs-tools/unsquash-2.c | 16 +++++ - squashfs-tools/unsquash-3.c | 6 ++ - squashfs-tools/unsquash-4.c | 6 ++ - squashfs-tools/unsquashfs.h | 4 ++ - 8 files changed, 173 insertions(+), 2 deletions(-) - create mode 100644 squashfs-tools/unsquash-12.c - -diff --git a/squashfs-tools/Makefile b/squashfs-tools/Makefile -index 5795d0d..417f2ba 100755 ---- a/squashfs-tools/Makefile -+++ b/squashfs-tools/Makefile -@@ -160,8 +160,8 @@ MKSQUASHFS_OBJS = mksquashfs.o read_fs.o action.o swap.o pseudo.o compressor.o \ - caches-queues-lists.o reader.o tar.o - - UNSQUASHFS_OBJS = unsquashfs.o unsquash-1.o unsquash-2.o unsquash-3.o \ -- unsquash-4.o unsquash-123.o unsquash-34.o unsquash-1234.o swap.o \ -- compressor.o unsquashfs_info.o -+ unsquash-4.o unsquash-123.o unsquash-34.o unsquash-1234.o unsquash-12.o \ -+ swap.o compressor.o unsquashfs_info.o - - CFLAGS ?= -O2 - CFLAGS += $(EXTRA_CFLAGS) $(INCLUDEDIR) -D_FILE_OFFSET_BITS=64 \ -@@ -393,6 +393,8 @@ unsquash-34.o: unsquashfs.h unsquash-34.c unsquashfs_error.h - - unsquash-1234.o: unsquash-1234.c unsquashfs_error.h - -+unsquash-1234.o: unsquash-12.c -+ - unsquashfs_xattr.o: unsquashfs_xattr.c unsquashfs.h squashfs_fs.h xattr.h unsquashfs_error.h - - unsquashfs_info.o: unsquashfs.h squashfs_fs.h unsquashfs_error.h -diff --git a/squashfs-tools/unsquash-1.c b/squashfs-tools/unsquash-1.c -index b604434..88866fc 100644 ---- a/squashfs-tools/unsquash-1.c -+++ b/squashfs-tools/unsquash-1.c -@@ -370,6 +370,12 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse - } - } - -+ /* check directory for duplicate names. Need to sort directory first */ -+ sort_directory(dir); -+ if(check_directory(dir) == FALSE) { -+ ERROR("File system corrupted: directory has duplicate names\n"); -+ goto corrupted; -+ } - return dir; - - corrupted: -diff --git a/squashfs-tools/unsquash-12.c b/squashfs-tools/unsquash-12.c -new file mode 100644 -index 0000000..61bf128 ---- /dev/null -+++ b/squashfs-tools/unsquash-12.c -@@ -0,0 +1,110 @@ -+/* -+ * Unsquash a squashfs filesystem. This is a highly compressed read only -+ * filesystem. -+ * -+ * Copyright (c) 2021 -+ * Phillip Lougher <phillip@squashfs.org.uk> -+ * -+ * This program is free software; you can redistribute it and/or -+ * modify it under the terms of the GNU General Public License -+ * as published by the Free Software Foundation; either version 2, -+ * or (at your option) any later version. -+ * -+ * This program is distributed in the hope that it will be useful, -+ * but WITHOUT ANY WARRANTY; without even the implied warranty of -+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -+ * GNU General Public License for more details. -+ * -+ * You should have received a copy of the GNU General Public License -+ * along with this program; if not, write to the Free Software -+ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. -+ * -+ * unsquash-12.c -+ * -+ * Helper functions used by unsquash-1 and unsquash-2. -+ */ -+ -+#include "unsquashfs.h" -+ -+/* -+ * Bottom up linked list merge sort. -+ * -+ */ -+void sort_directory(struct dir *dir) -+{ -+ struct dir_ent *cur, *l1, *l2, *next; -+ int len1, len2, stride = 1; -+ -+ if(dir->dir_count < 2) -+ return; -+ -+ /* -+ * We can consider our linked-list to be made up of stride length -+ * sublists. Eacn iteration around this loop merges adjacent -+ * stride length sublists into larger 2*stride sublists. We stop -+ * when stride becomes equal to the entire list. -+ * -+ * Initially stride = 1 (by definition a sublist of 1 is sorted), and -+ * these 1 element sublists are merged into 2 element sublists, which -+ * are then merged into 4 element sublists and so on. -+ */ -+ do { -+ l2 = dir->dirs; /* head of current linked list */ -+ cur = NULL; /* empty output list */ -+ -+ /* -+ * Iterate through the linked list, merging adjacent sublists. -+ * On each interation l2 points to the next sublist pair to be -+ * merged (if there's only one sublist left this is simply added -+ * to the output list) -+ */ -+ while(l2) { -+ l1 = l2; -+ for(len1 = 0; l2 && len1 < stride; len1 ++, l2 = l2->next); -+ len2 = stride; -+ -+ /* -+ * l1 points to first sublist. -+ * l2 points to second sublist. -+ * Merge them onto the output list -+ */ -+ while(len1 && l2 && len2) { -+ if(strcmp(l1->name, l2->name) <= 0) { -+ next = l1; -+ l1 = l1->next; -+ len1 --; -+ } else { -+ next = l2; -+ l2 = l2->next; -+ len2 --; -+ } -+ -+ if(cur) { -+ cur->next = next; -+ cur = next; -+ } else -+ dir->dirs = cur = next; -+ } -+ /* -+ * One sublist is now empty, copy the other one onto the -+ * output list -+ */ -+ for(; len1; len1 --, l1 = l1->next) { -+ if(cur) { -+ cur->next = l1; -+ cur = l1; -+ } else -+ dir->dirs = cur = l1; -+ } -+ for(; l2 && len2; len2 --, l2 = l2->next) { -+ if(cur) { -+ cur->next = l2; -+ cur = l2; -+ } else -+ dir->dirs = cur = l2; -+ } -+ } -+ cur->next = NULL; -+ stride = stride << 1; -+ } while(stride < dir->dir_count); -+} -diff --git a/squashfs-tools/unsquash-1234.c b/squashfs-tools/unsquash-1234.c -index e389f8d..98a81ed 100644 ---- a/squashfs-tools/unsquash-1234.c -+++ b/squashfs-tools/unsquash-1234.c -@@ -72,3 +72,24 @@ void squashfs_closedir(struct dir *dir) - - free(dir); - } -+ -+ -+/* -+ * Check directory for duplicate names. As the directory should be sorted, -+ * duplicates will be consecutive. Obviously we also need to check if the -+ * directory has been deliberately unsorted, to evade this check. -+ */ -+int check_directory(struct dir *dir) -+{ -+ int i; -+ struct dir_ent *ent; -+ -+ if(dir->dir_count < 2) -+ return TRUE; -+ -+ for(ent = dir->dirs, i = 0; i < dir->dir_count - 1; ent = ent->next, i++) -+ if(strcmp(ent->name, ent->next->name) >= 0) -+ return FALSE; -+ -+ return TRUE; -+} -diff --git a/squashfs-tools/unsquash-2.c b/squashfs-tools/unsquash-2.c -index 956f96f..0e36f7d 100644 ---- a/squashfs-tools/unsquash-2.c -+++ b/squashfs-tools/unsquash-2.c -@@ -29,6 +29,7 @@ - static squashfs_fragment_entry_2 *fragment_table; - static unsigned int *uid_table, *guid_table; - static squashfs_operations ops; -+static int needs_sorting = FALSE; - - - static void read_block_list(unsigned int *block_list, long long start, -@@ -463,6 +464,17 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse - } - } - -+ if(needs_sorting) -+ sort_directory(dir); -+ -+ /* check directory for duplicate names and sorting */ -+ if(check_directory(dir) == FALSE) { -+ if(needs_sorting) -+ ERROR("File system corrupted: directory has duplicate names\n"); -+ else -+ ERROR("File system corrupted: directory has duplicate names or is unsorted\n"); -+ goto corrupted; -+ } - return dir; - - corrupted: -@@ -596,6 +608,10 @@ int read_super_2(squashfs_operations **s_ops, void *s) - * 2.x filesystems use gzip compression. - */ - comp = lookup_compressor("gzip"); -+ -+ if(sBlk_3->s_minor == 0) -+ needs_sorting = TRUE; -+ - return TRUE; - } - -diff --git a/squashfs-tools/unsquash-3.c b/squashfs-tools/unsquash-3.c -index 835a574..0123562 100644 ---- a/squashfs-tools/unsquash-3.c -+++ b/squashfs-tools/unsquash-3.c -@@ -497,6 +497,12 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse - } - } - -+ /* check directory for duplicate names and sorting */ -+ if(check_directory(dir) == FALSE) { -+ ERROR("File system corrupted: directory has duplicate names or is unsorted\n"); -+ goto corrupted; -+ } -+ - return dir; - - corrupted: -diff --git a/squashfs-tools/unsquash-4.c b/squashfs-tools/unsquash-4.c -index fd7ab6c..7443d55 100644 ---- a/squashfs-tools/unsquash-4.c -+++ b/squashfs-tools/unsquash-4.c -@@ -434,6 +434,12 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse - } - } - -+ /* check directory for duplicate names and sorting */ -+ if(check_directory(dir) == FALSE) { -+ ERROR("File system corrupted: directory has duplicate names or is unsorted\n"); -+ goto corrupted; -+ } -+ - return dir; - - corrupted: -diff --git a/squashfs-tools/unsquashfs.h b/squashfs-tools/unsquashfs.h -index f8cf78c..bf2a80d 100644 ---- a/squashfs-tools/unsquashfs.h -+++ b/squashfs-tools/unsquashfs.h -@@ -293,4 +293,8 @@ extern long long *alloc_index_table(int); - /* unsquash-1234.c */ - extern int check_name(char *, int); - extern void squashfs_closedir(struct dir *); -+extern int check_directory(struct dir *); -+ -+/* unsquash-12.c */ -+extern void sort_directory(struct dir *); - #endif --- -2.33.1 - |