From 09de4ef3f33540069a37e9fe6e13081984b77511 Mon Sep 17 00:00:00 2001 From: Kai Kang Date: Fri, 10 Sep 2021 13:01:44 +0800 Subject: squashfs-tools: fix CVE-2021-40153 Backport patch to fix CVE-2021-40153, and remove version update in unsquashfs.c for compatible. CVE: CVE-2021-40153 Ref: * https://security-tracker.debian.org/tracker/CVE-2021-40153 Signed-off-by: Kai Kang Signed-off-by: Anuj Mittal --- .../squashfs-tools/files/CVE-2021-40153.patch | 253 +++++++++++++++++++++ .../squashfs-tools/squashfs-tools_git.bb | 1 + 2 files changed, 254 insertions(+) create mode 100644 meta/recipes-devtools/squashfs-tools/files/CVE-2021-40153.patch diff --git a/meta/recipes-devtools/squashfs-tools/files/CVE-2021-40153.patch b/meta/recipes-devtools/squashfs-tools/files/CVE-2021-40153.patch new file mode 100644 index 0000000000..95e2534ee4 --- /dev/null +++ b/meta/recipes-devtools/squashfs-tools/files/CVE-2021-40153.patch @@ -0,0 +1,253 @@ +Backport patch to fix CVE-2021-40153, and remove version update in unsquashfs.c +for compatible. + +Upstream-Status: Backport [https://github.com/plougher/squashfs-tools/commit/79b5a55] +CVE: CVE-2021-40153 + +Signed-off-by: Kai Kang + +From 79b5a555058eef4e1e7ff220c344d39f8cd09646 Mon Sep 17 00:00:00 2001 +From: Phillip Lougher +Date: Sat, 16 Jan 2021 20:08:55 +0000 +Subject: [PATCH] Unsquashfs: fix write outside destination directory exploit + +An issue on Github (https://github.com/plougher/squashfs-tools/issues/72) +shows how some specially crafted Squashfs filesystems containing +invalid file names (with '/' and ..) can cause Unsquashfs to write +files outside of the destination directory. + +This commit fixes this exploit by checking all names for +validity. + +In doing so I have also added checks for '.' and for names that +are shorter than they should be (names in the file system should +not have '\0' terminators). + +Signed-off-by: Phillip Lougher +--- + squashfs-tools/Makefile | 5 ++- + squashfs-tools/unsquash-1.c | 9 +++++- + squashfs-tools/unsquash-1234.c | 58 ++++++++++++++++++++++++++++++++++ + squashfs-tools/unsquash-2.c | 9 +++++- + squashfs-tools/unsquash-3.c | 9 +++++- + squashfs-tools/unsquash-4.c | 9 +++++- + squashfs-tools/unsquashfs.h | 5 ++- + 7 files changed, 98 insertions(+), 6 deletions(-) + create mode 100644 squashfs-tools/unsquash-1234.c + +diff --git a/squashfs-tools/Makefile b/squashfs-tools/Makefile +index aee4b960..20feaca2 100644 +--- a/squashfs-tools/Makefile ++++ b/squashfs-tools/Makefile +@@ -156,7 +156,8 @@ MKSQUASHFS_OBJS = mksquashfs.o read_fs.o action.o swap.o pseudo.o compressor.o \ + caches-queues-lists.o + + UNSQUASHFS_OBJS = unsquashfs.o unsquash-1.o unsquash-2.o unsquash-3.o \ +- unsquash-4.o unsquash-123.o unsquash-34.o swap.o compressor.o unsquashfs_info.o ++ unsquash-4.o unsquash-123.o unsquash-34.o unsquash-1234.o swap.o \ ++ compressor.o unsquashfs_info.o + + CFLAGS ?= -O2 + CFLAGS += $(EXTRA_CFLAGS) $(INCLUDEDIR) -D_FILE_OFFSET_BITS=64 \ +@@ -350,6 +351,8 @@ unsquash-123.o: unsquashfs.h unsquash-123.c squashfs_fs.h squashfs_compat.h + + unsquash-34.o: unsquashfs.h unsquash-34.c + ++unsquash-1234.o: unsquash-1234.c ++ + unsquashfs_xattr.o: unsquashfs_xattr.c unsquashfs.h squashfs_fs.h xattr.h + + unsquashfs_info.o: unsquashfs.h squashfs_fs.h +diff --git a/squashfs-tools/unsquash-1.c b/squashfs-tools/unsquash-1.c +index 34eced36..28326cb1 100644 +--- a/squashfs-tools/unsquash-1.c ++++ b/squashfs-tools/unsquash-1.c +@@ -2,7 +2,7 @@ + * Unsquash a squashfs filesystem. This is a highly compressed read only + * filesystem. + * +- * Copyright (c) 2009, 2010, 2011, 2012, 2019 ++ * Copyright (c) 2009, 2010, 2011, 2012, 2019, 2021 + * Phillip Lougher + * + * This program is free software; you can redistribute it and/or +@@ -285,6 +285,13 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse + memcpy(dire->name, directory_table + bytes, + dire->size + 1); + dire->name[dire->size + 1] = '\0'; ++ ++ /* check name for invalid characters (i.e /, ., ..) */ ++ if(check_name(dire->name, dire->size + 1) == FALSE) { ++ ERROR("File system corrupted: invalid characters in name\n"); ++ goto corrupted; ++ } ++ + TRACE("squashfs_opendir: directory entry %s, inode " + "%d:%d, type %d\n", dire->name, + dirh.start_block, dire->offset, dire->type); +diff --git a/squashfs-tools/unsquash-1234.c b/squashfs-tools/unsquash-1234.c +new file mode 100644 +index 00000000..c2d4f42b +--- /dev/null ++++ b/squashfs-tools/unsquash-1234.c +@@ -0,0 +1,58 @@ ++/* ++ * Unsquash a squashfs filesystem. This is a highly compressed read only ++ * filesystem. ++ * ++ * Copyright (c) 2021 ++ * Phillip Lougher ++ * ++ * 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-1234.c ++ * ++ * Helper functions used by unsquash-1, unsquash-2, unsquash-3 and ++ * unsquash-4. ++ */ ++ ++#define TRUE 1 ++#define FALSE 0 ++/* ++ * Check name for validity, name should not ++ * - be ".", "./", or ++ * - be "..", "../" or ++ * - have a "/" anywhere in the name, or ++ * - be shorter than the expected size ++ */ ++int check_name(char *name, int size) ++{ ++ char *start = name; ++ ++ if(name[0] == '.') { ++ if(name[1] == '.') ++ name++; ++ if(name[1] == '/' || name[1] == '\0') ++ return FALSE; ++ } ++ ++ while(name[0] != '/' && name[0] != '\0') ++ name ++; ++ ++ if(name[0] == '/') ++ return FALSE; ++ ++ if((name - start) != size) ++ return FALSE; ++ ++ return TRUE; ++} +diff --git a/squashfs-tools/unsquash-2.c b/squashfs-tools/unsquash-2.c +index 4b3d767e..474064e1 100644 +--- a/squashfs-tools/unsquash-2.c ++++ b/squashfs-tools/unsquash-2.c +@@ -2,7 +2,7 @@ + * Unsquash a squashfs filesystem. This is a highly compressed read only + * filesystem. + * +- * Copyright (c) 2009, 2010, 2013, 2019 ++ * Copyright (c) 2009, 2010, 2013, 2019, 2021 + * Phillip Lougher + * + * This program is free software; you can redistribute it and/or +@@ -386,6 +386,13 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse + memcpy(dire->name, directory_table + bytes, + dire->size + 1); + dire->name[dire->size + 1] = '\0'; ++ ++ /* check name for invalid characters (i.e /, ., ..) */ ++ if(check_name(dire->name, dire->size + 1) == FALSE) { ++ ERROR("File system corrupted: invalid characters in name\n"); ++ goto corrupted; ++ } ++ + TRACE("squashfs_opendir: directory entry %s, inode " + "%d:%d, type %d\n", dire->name, + dirh.start_block, dire->offset, dire->type); +diff --git a/squashfs-tools/unsquash-3.c b/squashfs-tools/unsquash-3.c +index 02c31fc5..65cfe4d9 100644 +--- a/squashfs-tools/unsquash-3.c ++++ b/squashfs-tools/unsquash-3.c +@@ -2,7 +2,7 @@ + * Unsquash a squashfs filesystem. This is a highly compressed read only + * filesystem. + * +- * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2019 ++ * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2019, 2021 + * Phillip Lougher + * + * This program is free software; you can redistribute it and/or +@@ -413,6 +413,13 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse + memcpy(dire->name, directory_table + bytes, + dire->size + 1); + dire->name[dire->size + 1] = '\0'; ++ ++ /* check name for invalid characters (i.e /, ., ..) */ ++ if(check_name(dire->name, dire->size + 1) == FALSE) { ++ ERROR("File system corrupted: invalid characters in name\n"); ++ goto corrupted; ++ } ++ + TRACE("squashfs_opendir: directory entry %s, inode " + "%d:%d, type %d\n", dire->name, + dirh.start_block, dire->offset, dire->type); +diff --git a/squashfs-tools/unsquash-4.c b/squashfs-tools/unsquash-4.c +index 8475835c..aa23a841 100644 +--- a/squashfs-tools/unsquash-4.c ++++ b/squashfs-tools/unsquash-4.c +@@ -2,7 +2,7 @@ + * Unsquash a squashfs filesystem. This is a highly compressed read only + * filesystem. + * +- * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2019 ++ * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2019, 2021 + * Phillip Lougher + * + * This program is free software; you can redistribute it and/or +@@ -349,6 +349,13 @@ static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offse + memcpy(dire->name, directory_table + bytes, + dire->size + 1); + dire->name[dire->size + 1] = '\0'; ++ ++ /* check name for invalid characters (i.e /, ., ..) */ ++ if(check_name(dire->name, dire->size + 1) == FALSE) { ++ ERROR("File system corrupted: invalid characters in name\n"); ++ goto corrupted; ++ } ++ + TRACE("squashfs_opendir: directory entry %s, inode " + "%d:%d, type %d\n", dire->name, + dirh.start_block, dire->offset, dire->type); +diff --git a/squashfs-tools/unsquashfs.h b/squashfs-tools/unsquashfs.h +index 934618b2..db1da7a0 100644 +--- a/squashfs-tools/unsquashfs.h ++++ b/squashfs-tools/unsquashfs.h +@@ -4,7 +4,7 @@ + * Unsquash a squashfs filesystem. This is a highly compressed read only + * filesystem. + * +- * Copyright (c) 2009, 2010, 2013, 2014, 2019 ++ * Copyright (c) 2009, 2010, 2013, 2014, 2019, 2021 + * Phillip Lougher + * + * This program is free software; you can redistribute it and/or +@@ -261,4 +261,7 @@ extern int read_ids(int, long long, long long, unsigned int **); + + /* unsquash-34.c */ + extern long long *alloc_index_table(int); ++ ++/* unsquash-1234.c */ ++extern int check_name(char *, int); + #endif diff --git a/meta/recipes-devtools/squashfs-tools/squashfs-tools_git.bb b/meta/recipes-devtools/squashfs-tools/squashfs-tools_git.bb index 2b1409d78d..083e597b03 100644 --- a/meta/recipes-devtools/squashfs-tools/squashfs-tools_git.bb +++ b/meta/recipes-devtools/squashfs-tools/squashfs-tools_git.bb @@ -11,6 +11,7 @@ PV = "4.4" SRCREV = "52eb4c279cd283ed9802dd1ceb686560b22ffb67" SRC_URI = "git://github.com/plougher/squashfs-tools.git;protocol=https \ file://0001-squashfs-tools-fix-build-failure-against-gcc-10.patch;striplevel=2 \ + file://CVE-2021-40153.patch;striplevel=2 \ " S = "${WORKDIR}/git/squashfs-tools" -- cgit 1.2.3-korg