Update advisory format and introduce some automation

Simplify the advisory format by dropping the -Backport tags and instead
stick to using just the -Commit tags.  To identify backports, put a
substring of git-describe into the release version in the brackets next
to the commit ref.  This way, it not only identifies that the fix (or
regression) is on the release/2.YY/master branch, it also disambiguates
regressions/fixes in the branch from those in the tarball.

Add a README to make it easier for consumers to understand the format.
Additionally, the Release wiki needs to be updated to inform the release
manager to:

1. Generate a NEWS snipped from the advisories directory

AND

2. on release/2.YY/master, replace the advisories directory with a text
   file pointing to the advisories directory in master so that we don't
   have to update multiple locations.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Andreas K. Hüttel <dilfridge@gentoo.org>

advisories/GLIBC-SA-2023-0001

@@ -11,4 +11,4 @@ CVE-Id: CVE-2023-25139
 Public-Date: 2023-02-02
 Vulnerable-Commit: e88b9f0e5cc50cab57a299dc7efe1a4eb385161d (2.37)
 Fix-Commit: c980549cc6a1c03c23cc2fe3e7b0fe626a0364b0 (2.38)
-Fix-Backport: 07b9521fc6369d000216b96562ff7c0ed32a16c4 (2.37)
+Fix-Commit: 07b9521fc6369d000216b96562ff7c0ed32a16c4 (2.37-4)

advisories/GLIBC-SA-2023-0002

@@ -10,6 +10,6 @@ CVE-Id: CVE-2023-4527
 Public-Date: 2023-09-12
 Vulnerable-Commit: f282cdbe7f436c75864e5640a409a10485e9abb2 (2.36)
 Fix-Commit: bd77dd7e73e3530203be1c52c8a29d08270cb25d (2.39)
-Fix-Backport: 4ea972b7edd7e36610e8cde18bf7a8149d7bac4f (2.36)
+Fix-Commit: 4ea972b7edd7e36610e8cde18bf7a8149d7bac4f (2.36-113)
-Fix-Backport: b7529346025a130fee483d42178b5c118da971bb (2.37)
+Fix-Commit: b7529346025a130fee483d42178b5c118da971bb (2.37-38)
-Fix-Backport: b25508dd774b617f99419bdc3cf2ace4560cd2d6 (2.38)
+Fix-Commit: b25508dd774b617f99419bdc3cf2ace4560cd2d6 (2.38-19)

advisories/GLIBC-SA-2023-0003

@@ -8,8 +8,8 @@ arbitrary memory.
 CVE-Id: CVE-2023-4806
 Public-Date: 2023-09-12
 Fix-Commit: 973fe93a5675c42798b2161c6f29c01b0e243994 (2.39)
-Fix-Backport: e09ee267c03e3150c2c9ba28625ab130705a485e (2.34)
+Fix-Commit: e09ee267c03e3150c2c9ba28625ab130705a485e (2.34-420)
-Fix-Backport: e3ccb230a961b4797510e6a1f5f21fd9021853e7 (2.35)
+Fix-Commit: e3ccb230a961b4797510e6a1f5f21fd9021853e7 (2.35-270)
-Fix-Backport: a9728f798ec7f05454c95637ee6581afaa9b487d (2.36)
+Fix-Commit: a9728f798ec7f05454c95637ee6581afaa9b487d (2.36-115)
-Fix-Backport: 6529a7466c935f36e9006b854d6f4e1d4876f942 (2.37)
+Fix-Commit: 6529a7466c935f36e9006b854d6f4e1d4876f942 (2.37-39)
-Fix-Backport: 00ae4f10b504bc4564e9f22f00907093f1ab9338 (2.38)
+Fix-Commit: 00ae4f10b504bc4564e9f22f00907093f1ab9338 (2.38-20)

advisories/GLIBC-SA-2023-0004

@@ -9,8 +9,8 @@ CVE-Id: CVE-2023-4911
 Public-Date: 2023-10-03
 Vulnerable-Commit: 2ed18c5b534d9e92fc006202a5af0df6b72e7aca (2.34)
 Fix-Commit: 1056e5b4c3f2d90ed2b4a55f96add28da2f4c8fa (2.39)
-Fix-Backport: dcc367f148bc92e7f3778a125f7a416b093964d9 (2.34)
+Fix-Commit: dcc367f148bc92e7f3778a125f7a416b093964d9 (2.34-423)
-Fix-Backport: c84018a05aec80f5ee6f682db0da1130b0196aef (2.35)
+Fix-Commit: c84018a05aec80f5ee6f682db0da1130b0196aef (2.35-274)
-Fix-Backport: 22955ad85186ee05834e47e665056148ca07699c (2.36)
+Fix-Commit: 22955ad85186ee05834e47e665056148ca07699c (2.36-118)
-Fix-Backport: b4e23c75aea756b4bddc4abcf27a1c6dca8b6bd3 (2.37)
+Fix-Commit: b4e23c75aea756b4bddc4abcf27a1c6dca8b6bd3 (2.37-45)
-Fix-Backport: 750a45a783906a19591fb8ff6b7841470f1f5701 (2.38)
+Fix-Commit: 750a45a783906a19591fb8ff6b7841470f1f5701 (2.38-27)

advisories/GLIBC-SA-2023-0005

@@ -6,15 +6,13 @@ flags set.
 
 CVE-Id: CVE-2023-5156
 Public-Date: 2023-09-25
-Vulnerable-Commit: 973fe93a5675c42798b2161c6f29c01b0e243994 (pre-2.39)
+Vulnerable-Commit: e09ee267c03e3150c2c9ba28625ab130705a485e (2.34-420)
-Fix-Commit: ec6b95c3303c700eb89eebeda2d7264cc184a796 (2.39)
+Vulnerable-Commit: e3ccb230a961b4797510e6a1f5f21fd9021853e7 (2.35-270)
-Vulnerable-Backport: e09ee267c03e3150c2c9ba28625ab130705a485e (2.34)
+Vulnerable-Commit: a9728f798ec7f05454c95637ee6581afaa9b487d (2.36-115)
-Vulnerable-Backport: e3ccb230a961b4797510e6a1f5f21fd9021853e7 (2.35)
+Vulnerable-Commit: 6529a7466c935f36e9006b854d6f4e1d4876f942 (2.37-39)
-Vulnerable-Backport: a9728f798ec7f05454c95637ee6581afaa9b487d (2.36)
+Vulnerable-Commit: 00ae4f10b504bc4564e9f22f00907093f1ab9338 (2.38-20)
-Vulnerable-Backport: 6529a7466c935f36e9006b854d6f4e1d4876f942 (2.37)
+Fix-Commit: 8006457ab7e1cd556b919f477348a96fe88f2e49 (2.34-421)
-Vulnerable-Backport: 00ae4f10b504bc4564e9f22f00907093f1ab9338 (2.38)
+Fix-Commit: 17092c0311f954e6f3c010f73ce3a78c24ac279a (2.35-272)
-Fix-Backport: 8006457ab7e1cd556b919f477348a96fe88f2e49 (2.34)
+Fix-Commit: 856bac55f98dc840e7c27cfa82262b933385de90 (2.36-116)
-Fix-Backport: 17092c0311f954e6f3c010f73ce3a78c24ac279a (2.35)
+Fix-Commit: 4473d1b87d04b25cdd0e0354814eeaa421328268 (2.37-42)
-Fix-Backport: 856bac55f98dc840e7c27cfa82262b933385de90 (2.36)
+Fix-Commit: 5ee59ca371b99984232d7584fe2b1a758b4421d3 (2.38-24)
-Fix-Backport: 4473d1b87d04b25cdd0e0354814eeaa421328268 (2.37)
-Fix-Backport: 5ee59ca371b99984232d7584fe2b1a758b4421d3 (2.38)

advisories/README

@@ -0,0 +1,73 @@
+GNU C Library Security Advisory Format
+======================================
+
+Security advisories in this directory follow a simple git commit log
+format, with a heading and free-format description augmented with tags
+to allow parsing key information.  References to code changes are
+specific to the glibc repository and follow a specific format:
+
+  Tag-name: <commit-ref> (release-version)
+
+The <commit-ref> indicates a specific commit in the repository.  The
+release-version indicates the publicly consumable release in which this
+commit is known to exist.  The release-version is derived from the
+git-describe format, (i.e. stripped out from glibc-2.34.NNN-gxxxx) and
+is of the form 2.34-NNN.  If the -NNN suffix is absent, it means that
+the change is in that release tarball, otherwise the change is on the
+release/2.YY/master branch and not in any released tarball.
+
+The following tags are currently being used:
+
+CVE-Id:
+This is the CVE-Id assigned under the CVE Program
+(https://www.cve.org/).
+
+Public-Date:
+The date this issue became publicly known.
+
+Vulnerable-Commit:
+The commit that introduced this vulnerability.  There could be multiple
+entries, one for each release branch in the glibc repository; the
+release-version portion of this tag should tell you which branch this is
+on.
+
+Fix-Commit:
+The commit that fixed this vulnerability.  There could be multiple
+entries for each release branch in the glibc repository, indicating that
+all of those commits contributed to fixing that issue in each of those
+branches.
+
+Adding an Advisory
+------------------
+
+An advisory for a CVE needs to be added on the master branch in two steps:
+
+1. Add the text of the advisory without any Fix-Commit tags along with
+   the fix for the CVE.  Add the Vulnerable-Commit tag, if applicable.
+   The advisories directory does not exist in release branches, so keep
+   the advisory text commit distinct from the code changes, to ease
+   backports.  Ask for the GLIBC-SA advisory number from the security
+   team.
+
+2. Finish all backports on release branches and then back on the msater
+   branch, add all commit refs to the advisory using the Fix-Commit
+   tags.  Don't bother adding the release-version subscript since the
+   next step will overwrite it.
+
+3. Run the process-advisories.sh script in the scripts directory on the
+   advisory:
+
+     scripts/process-advisories.sh update GLIBC-SA-YYYY-NNNN
+
+   (replace YYYY-NNNN with the actual advisory number).
+
+4. Verify the updated advisory and push the result.
+
+Getting a NEWS snippet from advisories
+--------------------------------------
+
+Run:
+
+  scripts/process-advisories.sh news
+
+and copy the content into the NEWS file.

scripts/process-advisories.sh

@@ -0,0 +1,85 @@
+#!/bin/bash -e
+# Copyright The GNU Toolchain Authors.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+
+if ! [ -d advisories ]; then
+  echo "error: Run me from the toplevel directory of the glibc repository."
+  exit 1
+fi
+
+command=$1
+
+usage () {
+    cat >&2 <<EOF
+usage: $0 {update|news}
+EOF
+    exit 1
+}
+
+command="$1"
+
+case "$command" in
+    update|news)
+    ;;
+    *)
+        usage
+        ;;
+esac
+
+get_rel() {
+  rel=$(git describe $1 | sed 's/glibc-\([^g]\+\)-g.*/\1/')
+  # If the latest tag for the commit is the development tag, then increment
+  # the release version.
+  if echo $rel | grep -q "\.9000"; then
+    rel=$(echo $rel | sed 's/2\.\([0-9]\+\)\.9000.*/\1/')
+    rel="2.$((rel+1))"
+  fi
+  echo $rel
+}
+
+advisories_update() {
+  advisory=$1
+
+  if [ -z $1 ]; then
+    echo "Usage: $0 update GLIBC-SA-YYYY-NNNN"
+    exit 1
+  fi
+
+  advisory_file=advisories/$advisory
+
+  grep --color=none Commit $advisory_file | awk '{printf "%s %s\n", $1, $2}' |
+    while read t r; do
+      rel=$(get_rel $r)
+      echo "*** Updating: $t $r ($rel)"
+      sed -i "s/^$t $r.*/$t $r ($rel)/" $advisory_file
+    done
+}
+
+advisories_news() {
+  rel=$(get_rel "HEAD")
+  for f in $(grep -l "^Fix-Commit: .* ($rel)$" advisories/*); do
+    echo -e "  $(basename $f):"
+    cve_id=$(sed -n 's/CVE-Id: \(.*\)/\1/p' $f)
+    echo "$(head -1 $f) ($cve_id)" | fold -w 68 -s |
+      while read line; do
+	echo "    $line"
+      done
+    echo
+  done
+}
+
+advisories_$command $2

scripts/process-fixed-cves.sh

@@ -1,41 +0,0 @@
-#!/bin/bash -e
-# Copyright The GNU Toolchain Authors.
-# This file is part of the GNU C Library.
-#
-# The GNU C Library is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2.1 of the License, or (at your option) any later version.
-#
-# The GNU C Library 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
-# Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public
-# License along with the GNU C Library; if not, see
-# <https://www.gnu.org/licenses/>.
-
-if ! [ -d advisories ]; then
-  echo "error: Run me from the toplevel directory of the glibc repository."
-  exit 1
-fi
-
-release=$(echo RELEASE | gcc -E -include version.h -o - - | grep -v "^#")
-minor=$(echo __GLIBC_MINOR__ | gcc -E -include include/features.h -o - - |
-	grep -v "^#")
-
-if [ $release = "\"development\"" ]; then
-  cur_rel=2.$((minor + 1))
-else
-  cur_rel=2.$minor
-fi
-
-for f in $(grep -l "^Fix-Commit: .* ($cur_rel)$" advisories/*); do
-  echo -e "  $(basename $f):"
-  cve_id=$(sed -n 's/CVE-Id: \(.*\)/\1/p' $f)
-  echo "$(head -1 $f) ($cve_id)" | fold -w 68 -s | while read line; do
-    echo "    $line"
-  done
-  echo
-done