Move CVE information into advisories directory

One of the requirements to becoming a CVE Numbering Authority (CNA) is
to publish advisories.  Do this by maintaining a file for each CVE fixed
in the advisories directory in the source tree.  Links to the advisories
can then be shared as:

https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-YYYY-NNNN

The file format at the moment is rudimentary and derives from the git
commit format, i.e. a subject line and a potentially multi-paragraph
description and then tags to describe some meta information.  This is a
loose format at the moment and could change as we evolve this.

Also add a script process-fixed-cves.sh that processes these advisories
and generates a list to add to NEWS at release time.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

NEWS

@@ -75,25 +75,11 @@ Changes to build and runtime requirements:
 
 Security related changes:
 
-  CVE-2023-4527: If the system is configured in no-aaaa mode via
-  /etc/resolv.conf, getaddrinfo is called for the AF_UNSPEC address
-  family, and a DNS response is received over TCP that is larger than
-  2048 bytes, getaddrinfo may potentially disclose stack contents via
-  the returned address data, or crash.
+The following CVEs were fixed in this release, details of which can be
+found in the advisories directory of the release tarball:
 
-  CVE-2023-4806: When an NSS plugin only implements the
-  _gethostbyname2_r and _getcanonname_r callbacks, getaddrinfo could use
-  memory that was freed during buffer resizing, potentially causing a
-  crash or read or write to arbitrary memory.
-
-  CVE-2023-5156: The fix for CVE-2023-4806 introduced a memory leak when
-  an application calls getaddrinfo for AF_INET6 with AI_CANONNAME,
-  AI_ALL and AI_V4MAPPED flags set.
-
-  CVE-2023-4911: If a tunable of the form NAME=NAME=VAL is passed in the
-  environment of a setuid program and NAME is valid, it may result in a
-  buffer overflow, which could be exploited to achieve escalated
-  privileges.  This flaw was introduced in glibc 2.34.
+  [The release manager will add the list generated by
+  scripts/process-fixed-cves.sh just before the release.]
 
 The following bugs are resolved with this release:
 

advisories/GLIBC-SA-2023-0001

@@ -0,0 +1,14 @@
+printf: incorrect output for integers with thousands separator and width field
+
+When the printf family of functions is called with a format specifier
+that uses an <apostrophe> (enable grouping) and a minimum width
+specifier, the resulting output could be larger than reasonably expected
+by a caller that computed a tight bound on the buffer size.  The
+resulting larger than expected output could result in a buffer overflow
+in the printf family of functions.
+
+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)

advisories/GLIBC-SA-2023-0002

@@ -0,0 +1,15 @@
+getaddrinfo: Stack read overflow in no-aaaa mode
+
+If the system is configured in no-aaaa mode via /etc/resolv.conf,
+getaddrinfo is called for the AF_UNSPEC address family, and a DNS
+response is received over TCP that is larger than 2048 bytes,
+getaddrinfo may potentially disclose stack contents via the returned
+address data, or crash.
+
+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-Backport: b7529346025a130fee483d42178b5c118da971bb (2.37)
+Fix-Backport: b25508dd774b617f99419bdc3cf2ace4560cd2d6 (2.38)

advisories/GLIBC-SA-2023-0003

@@ -0,0 +1,15 @@
+getaddrinfo: Potential use-after-free
+
+When an NSS plugin only implements the _gethostbyname2_r and
+_getcanonname_r callbacks, getaddrinfo could use memory that was freed
+during buffer resizing, potentially causing a crash or read or write to
+arbitrary memory.
+
+CVE-Id: CVE-2023-4806
+Public-Date: 2023-09-12
+Fix-Commit: 973fe93a5675c42798b2161c6f29c01b0e243994 (2.39)
+Fix-Backport: e09ee267c03e3150c2c9ba28625ab130705a485e (2.34)
+Fix-Backport: e3ccb230a961b4797510e6a1f5f21fd9021853e7 (2.35)
+Fix-Backport: a9728f798ec7f05454c95637ee6581afaa9b487d (2.36)
+Fix-Backport: 6529a7466c935f36e9006b854d6f4e1d4876f942 (2.37)
+Fix-Backport: 00ae4f10b504bc4564e9f22f00907093f1ab9338 (2.38)

advisories/GLIBC-SA-2023-0004

@@ -0,0 +1,16 @@
+tunables: local privilege escalation through buffer overflow
+
+If a tunable of the form NAME=NAME=VAL is passed in the environment of a
+setuid program and NAME is valid, it may result in a buffer overflow,
+which could be exploited to achieve escalated privileges.  This flaw was
+introduced in glibc 2.34.
+
+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-Backport: c84018a05aec80f5ee6f682db0da1130b0196aef (2.35)
+Fix-Backport: 22955ad85186ee05834e47e665056148ca07699c (2.36)
+Fix-Backport: b4e23c75aea756b4bddc4abcf27a1c6dca8b6bd3 (2.37)
+Fix-Backport: 750a45a783906a19591fb8ff6b7841470f1f5701 (2.38)

advisories/GLIBC-SA-2023-0005

@@ -0,0 +1,20 @@
+getaddrinfo: DoS due to memory leak
+
+The fix for CVE-2023-4806 introduced a memory leak when an application
+calls getaddrinfo for AF_INET6 with AI_CANONNAME, AI_ALL and AI_V4MAPPED
+flags set.
+
+CVE-Id: CVE-2023-5156
+Public-Date: 2023-09-25
+Vulnerable-Commit: 973fe93a5675c42798b2161c6f29c01b0e243994 (pre-2.39)
+Fix-Commit: ec6b95c3303c700eb89eebeda2d7264cc184a796 (2.39)
+Vulnerable-Backport: e09ee267c03e3150c2c9ba28625ab130705a485e (2.34)
+Vulnerable-Backport: e3ccb230a961b4797510e6a1f5f21fd9021853e7 (2.35)
+Vulnerable-Backport: a9728f798ec7f05454c95637ee6581afaa9b487d (2.36)
+Vulnerable-Backport: 6529a7466c935f36e9006b854d6f4e1d4876f942 (2.37)
+Vulnerable-Backport: 00ae4f10b504bc4564e9f22f00907093f1ab9338 (2.38)
+Fix-Backport: 8006457ab7e1cd556b919f477348a96fe88f2e49 (2.34)
+Fix-Backport: 17092c0311f954e6f3c010f73ce3a78c24ac279a (2.35)
+Fix-Backport: 856bac55f98dc840e7c27cfa82262b933385de90 (2.36)
+Fix-Backport: 4473d1b87d04b25cdd0e0354814eeaa421328268 (2.37)
+Fix-Backport: 5ee59ca371b99984232d7584fe2b1a758b4421d3 (2.38)

scripts/process-fixed-cves.sh

@@ -0,0 +1,41 @@
+#!/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