From b16c9a295d5d2c5d2100bce11fffeae6beb766c5 Mon Sep 17 00:00:00 2001 From: Chen Qi Date: Wed, 7 May 2025 22:49:19 -0700 Subject: [PATCH] busybox: fix CVE-2023-39810 Backport patch to fix CVE-2023-39810. Note that the patch adds a config option which is disabled by default. So users wanting this feature needs to enable that option. Signed-off-by: Chen Qi Signed-off-by: Mathieu Dubois-Briand Signed-off-by: Richard Purdie --- ...allow-path-traversals-CVE-2023-39810.patch | 141 ++++++++++++++++++ meta/recipes-core/busybox/busybox_1.37.0.bb | 1 + 2 files changed, 142 insertions(+) create mode 100644 meta/recipes-core/busybox/busybox/0001-archival-disallow-path-traversals-CVE-2023-39810.patch diff --git a/meta/recipes-core/busybox/busybox/0001-archival-disallow-path-traversals-CVE-2023-39810.patch b/meta/recipes-core/busybox/busybox/0001-archival-disallow-path-traversals-CVE-2023-39810.patch new file mode 100644 index 0000000000..e76a4b128e --- /dev/null +++ b/meta/recipes-core/busybox/busybox/0001-archival-disallow-path-traversals-CVE-2023-39810.patch @@ -0,0 +1,141 @@ +From 42ce7953f48e5542297ff4381086b45ae28a02cf Mon Sep 17 00:00:00 2001 +From: Denys Vlasenko +Date: Wed, 2 Oct 2024 10:12:05 +0200 +Subject: [PATCH] archival: disallow path traversals (CVE-2023-39810) + +Create new configure option for archival/libarchive based extractions to +disallow path traversals. +As this is a paranoid option and might introduce backward +incompatibility, default it to no. + +Fixes: CVE-2023-39810 + +Based on the patch by Peter Kaestle + +function old new delta +data_extract_all 921 945 +24 +strip_unsafe_prefix 101 102 +1 +------------------------------------------------------------------------------ +(add/remove: 0/0 grow/shrink: 2/0 up/down: 25/0) Total: 25 bytes + +Signed-off-by: Denys Vlasenko + +CVE: CVE-2023-39810 + +Upstream-Status: Backport [https://git.busybox.net/busybox/commit/?id=9a8796436b9b0641e13480811902ea2ac57881d3] + +Signed-off-by: Chen Qi +--- + archival/Config.src | 11 +++++++++++ + archival/libarchive/data_extract_all.c | 8 ++++++++ + archival/libarchive/unsafe_prefix.c | 6 +++++- + scripts/kconfig/lxdialog/check-lxdialog.sh | 2 +- + testsuite/cpio.tests | 23 ++++++++++++++++++++++ + 5 files changed, 48 insertions(+), 2 deletions(-) + +diff --git a/archival/Config.src b/archival/Config.src +index 6f4f30c43..cbcd7217c 100644 +--- a/archival/Config.src ++++ b/archival/Config.src +@@ -35,4 +35,15 @@ config FEATURE_LZMA_FAST + This option reduces decompression time by about 25% at the cost of + a 1K bigger binary. + ++config FEATURE_PATH_TRAVERSAL_PROTECTION ++ bool "Prevent extraction of filenames with /../ path component" ++ default n ++ help ++ busybox tar and unzip remove "PREFIX/../" (if it exists) ++ from extracted names. ++ This option enables this behavior for all other unpacking applets, ++ such as cpio, ar, rpm. ++ GNU cpio 2.15 has NO such sanity check. ++# try other archivers and document their behavior? ++ + endmenu +diff --git a/archival/libarchive/data_extract_all.c b/archival/libarchive/data_extract_all.c +index 049c2c156..8a69711c1 100644 +--- a/archival/libarchive/data_extract_all.c ++++ b/archival/libarchive/data_extract_all.c +@@ -65,6 +65,14 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) + } while (--n != 0); + } + #endif ++#if ENABLE_FEATURE_PATH_TRAVERSAL_PROTECTION ++ /* Strip leading "/" and up to last "/../" path component */ ++ dst_name = (char *)strip_unsafe_prefix(dst_name); ++#endif ++// ^^^ This may be a problem if some applets do need to extract absolute names. ++// (Probably will need to invent ARCHIVE_ALLOW_UNSAFE_NAME flag). ++// You might think that rpm needs it, but in my tests rpm's internal cpio ++// archive has names like "./usr/bin/FOO", not "/usr/bin/FOO". + + if (archive_handle->ah_flags & ARCHIVE_CREATE_LEADING_DIRS) { + char *slash = strrchr(dst_name, '/'); +diff --git a/archival/libarchive/unsafe_prefix.c b/archival/libarchive/unsafe_prefix.c +index 33e487bf9..667081195 100644 +--- a/archival/libarchive/unsafe_prefix.c ++++ b/archival/libarchive/unsafe_prefix.c +@@ -14,7 +14,11 @@ const char* FAST_FUNC strip_unsafe_prefix(const char *str) + cp++; + continue; + } +- if (is_prefixed_with(cp, "/../"+1)) { ++ /* We are called lots of times. ++ * is_prefixed_with(cp, "../") is slower than open-coding it, ++ * with minimal code growth (~few bytes). ++ */ ++ if (cp[0] == '.' && cp[1] == '.' && cp[2] == '/') { + cp += 3; + continue; + } +diff --git a/scripts/kconfig/lxdialog/check-lxdialog.sh b/scripts/kconfig/lxdialog/check-lxdialog.sh +index 7003e026a..b91a54be6 100755 +--- a/scripts/kconfig/lxdialog/check-lxdialog.sh ++++ b/scripts/kconfig/lxdialog/check-lxdialog.sh +@@ -55,7 +55,7 @@ trap "rm -f $tmp" 0 1 2 3 15 + check() { + $cc -x c - -o $tmp 2>/dev/null <<'EOF' + #include CURSES_LOC +-main() {} ++int main() { return 0; } + EOF + if [ $? != 0 ]; then + echo " *** Unable to find the ncurses libraries or the" 1>&2 +diff --git a/testsuite/cpio.tests b/testsuite/cpio.tests +index 85e746589..a4462c53e 100755 +--- a/testsuite/cpio.tests ++++ b/testsuite/cpio.tests +@@ -154,6 +154,29 @@ testing "cpio -R with extract" \ + " "" "" + SKIP= + ++# Create an archive containing a file with "../dont_write" filename. ++# See that it will not be allowed to unpack. ++# NB: GNU cpio 2.15 DOES NOT do such checks. ++optional FEATURE_PATH_TRAVERSAL_PROTECTION ++rm -rf cpio.testdir ++mkdir -p cpio.testdir/prepare/inner ++echo "file outside of destination was written" > cpio.testdir/prepare/dont_write ++echo "data" > cpio.testdir/prepare/inner/to_extract ++mkdir -p cpio.testdir/extract ++testing "cpio extract file outside of destination" "\ ++(cd cpio.testdir/prepare/inner && echo -e '../dont_write\nto_extract' | cpio -o -H newc) | (cd cpio.testdir/extract && cpio -vi 2>&1) ++echo \$? ++ls cpio.testdir/dont_write 2>&1" \ ++"\ ++cpio: removing leading '../' from member names ++../dont_write ++to_extract ++1 blocks ++0 ++ls: cpio.testdir/dont_write: No such file or directory ++" "" "" ++SKIP= ++ + # Clean up + rm -rf cpio.testdir cpio.testdir2 2>/dev/null + +-- +2.48.1 + diff --git a/meta/recipes-core/busybox/busybox_1.37.0.bb b/meta/recipes-core/busybox/busybox_1.37.0.bb index c3131eb453..85f22ada53 100644 --- a/meta/recipes-core/busybox/busybox_1.37.0.bb +++ b/meta/recipes-core/busybox/busybox_1.37.0.bb @@ -53,6 +53,7 @@ SRC_URI = "https://busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \ file://0001-syslogd-fix-wrong-OPT_locallog-flag-detection.patch \ file://0002-start-stop-daemon-fix-tests.patch \ file://0003-start-stop-false.patch \ + file://0001-archival-disallow-path-traversals-CVE-2023-39810.patch \ " SRC_URI:append:libc-musl = " file://musl.cfg" SRC_URI:append:x86-64 = " file://sha_accel.cfg" -- 2.47.2