system/xz: apply ZDI-CAN-16587 patch. fixes #661.

2 files changed, 98 insertions, 2 deletions

diff --git a/system/xz/APKBUILD b/system/xz/APKBUILD
index 68fefcf80..7b8861fca 100644
--- a/system/xz/APKBUILD
+++ b/system/xz/APKBUILD
@@ -2,7 +2,7 @@
 # Maintainer: Dan Theisen <djt@hxx.in>
 pkgname=xz
 pkgver=5.2.5
-pkgrel=0
+pkgrel=1
 pkgdesc="Library and command line tools for XZ and LZMA compressed files"
 url="https://tukaani.org/xz/"
 arch="all"
@@ -12,6 +12,7 @@ makedepends=""
 subpackages="$pkgname-doc $pkgname-dev $pkgname-lang $pkgname-libs"
 source="https://tukaani.org/xz/xz-$pkgver.tar.gz
 	dont-use-libdir-for-pkgconfig.patch
+	CVE-2022-1271-xzgrep-ZDI-CAN-16587.patch
 	"
 
 build() {
@@ -46,4 +47,5 @@ package() {
 }
 
 sha512sums="7443674247deda2935220fbc4dfc7665e5bb5a260be8ad858c8bd7d7b9f0f868f04ea45e62eb17c0a5e6a2de7c7500ad2d201e2d668c48ca29bd9eea5a73a3ce  xz-5.2.5.tar.gz
-9310ae2568dd6ac474e3cb9895e1339ca2dbe8834f856edbb7d2264c0019bde4bbd94aa1edd34e5c8d0aed1f35a1877b0e053ed08a270835ea81e59c7be5edb3  dont-use-libdir-for-pkgconfig.patch"
+9310ae2568dd6ac474e3cb9895e1339ca2dbe8834f856edbb7d2264c0019bde4bbd94aa1edd34e5c8d0aed1f35a1877b0e053ed08a270835ea81e59c7be5edb3  dont-use-libdir-for-pkgconfig.patch
+52b16268e333399444f433a11ccf3a9b020a6914ed23fc8e082128fec596011d7c6863d47414d4c0f245d20ebed4b3a50b422599b4b88d66f6c6eb2e74b9a939  CVE-2022-1271-xzgrep-ZDI-CAN-16587.patch"
diff --git a/system/xz/CVE-2022-1271-xzgrep-ZDI-CAN-16587.patch b/system/xz/CVE-2022-1271-xzgrep-ZDI-CAN-16587.patch
new file mode 100644
index 000000000..406ded590
--- /dev/null
+++ b/system/xz/CVE-2022-1271-xzgrep-ZDI-CAN-16587.patch
@@ -0,0 +1,94 @@
+From 69d1b3fc29677af8ade8dc15dba83f0589cb63d6 Mon Sep 17 00:00:00 2001
+From: Lasse Collin <lasse.collin@tukaani.org>
+Date: Tue, 29 Mar 2022 19:19:12 +0300
+Subject: [PATCH] xzgrep: Fix escaping of malicious filenames (ZDI-CAN-16587).
+
+Malicious filenames can make xzgrep to write to arbitrary files
+or (with a GNU sed extension) lead to arbitrary code execution.
+
+xzgrep from XZ Utils versions up to and including 5.2.5 are
+affected. 5.3.1alpha and 5.3.2alpha are affected as well.
+This patch works for all of them.
+
+This bug was inherited from gzip's zgrep. gzip 1.12 includes
+a fix for zgrep.
+
+The issue with the old sed script is that with multiple newlines,
+the N-command will read the second line of input, then the
+s-commands will be skipped because it's not the end of the
+file yet, then a new sed cycle starts and the pattern space
+is printed and emptied. So only the last line or two get escaped.
+
+One way to fix this would be to read all lines into the pattern
+space first. However, the included fix is even simpler: All lines
+except the last line get a backslash appended at the end. To ensure
+that shell command substitution doesn't eat a possible trailing
+newline, a colon is appended to the filename before escaping.
+The colon is later used to separate the filename from the grep
+output so it is fine to add it here instead of a few lines later.
+
+The old code also wasn't POSIX compliant as it used \n in the
+replacement section of the s-command. Using \<newline> is the
+POSIX compatible method.
+
+LC_ALL=C was added to the two critical sed commands. POSIX sed
+manual recommends it when using sed to manipulate pathnames
+because in other locales invalid multibyte sequences might
+cause issues with some sed implementations. In case of GNU sed,
+these particular sed scripts wouldn't have such problems but some
+other scripts could have, see:
+
+    info '(sed)Locale Considerations'
+
+This vulnerability was discovered by:
+cleemy desu wayo working with Trend Micro Zero Day Initiative
+
+Thanks to Jim Meyering and Paul Eggert discussing the different
+ways to fix this and for coordinating the patch release schedule
+with gzip.
+---
+ src/scripts/xzgrep.in | 20 ++++++++++++--------
+ 1 file changed, 12 insertions(+), 8 deletions(-)
+
+diff --git a/src/scripts/xzgrep.in b/src/scripts/xzgrep.in
+index b180936..e5186ba 100644
+--- a/src/scripts/xzgrep.in
++++ b/src/scripts/xzgrep.in
+@@ -180,22 +180,26 @@ for i; do
+          { test $# -eq 1 || test $no_filename -eq 1; }; then
+       eval "$grep"
+     else
++      # Append a colon so that the last character will never be a newline
++      # which would otherwise get lost in shell command substitution.
++      i="$i:"
++
++      # Escape & \ | and newlines only if such characters are present
++      # (speed optimization).
+       case $i in
+       (*'
+ '* | *'&'* | *'\'* | *'|'*)
+-        i=$(printf '%s\n' "$i" |
+-            sed '
+-              $!N
+-              $s/[&\|]/\\&/g
+-              $s/\n/\\n/g
+-            ');;
++        i=$(printf '%s\n' "$i" | LC_ALL=C sed 's/[&\|]/\\&/g; $!s/$/\\/');;
+       esac
+-      sed_script="s|^|$i:|"
++
++      # $i already ends with a colon so don't add it here.
++      sed_script="s|^|$i|"
+ 
+       # Fail if grep or sed fails.
+       r=$(
+         exec 4>&1
+-        (eval "$grep" 4>&-; echo $? >&4) 3>&- | sed "$sed_script" >&3 4>&-
++        (eval "$grep" 4>&-; echo $? >&4) 3>&- |
++            LC_ALL=C sed "$sed_script" >&3 4>&-
+       ) || r=2
+       exit $r
+     fi >&3 5>&-
+-- 
+2.35.1
+