From 4bc114f972315651176ff72b32a7b4604086c9a5 Mon Sep 17 00:00:00 2001
From: Bryce Kwon <bryce@brycekwon.com>
Date: Thu, 1 Oct 2026 19:56:43 -1000
Subject: Pin the advisory classes with tests and name an empty author

Each class behind cgit's published advisories now has a check against
the current code, from a newline in a file name to shell syntax handed
to a filter. The feed also treated an ident with an empty name and an
empty address as present and wrote an empty person, which Atom forbids.
---
 source/ui-atom.c        |  16 ++++---
 tests/t0301-security.sh | 110 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+), 6 deletions(-)

diff --git a/source/ui-atom.c b/source/ui-atom.c
index b536437..39cadb8 100644
--- a/source/ui-atom.c
+++ b/source/ui-atom.c
@@ -88,9 +88,12 @@ static void print_email(const char *email)
 	if (end)
 		*end = '\0';
 
-	html("<email>");
-	xml_txt(start);
-	html("</email>\n");
+	// An empty element is no address at all, which Atom forbids.
+	if (*start) {
+		html("<email>");
+		xml_txt(start);
+		html("</email>\n");
+	}
 	free(copy);
 }
 
@@ -111,11 +114,12 @@ static void print_entry(struct commit *commit, const char *host)
 	html("</updated>\n");
 	html("<author>\n");
 	// A person construct must hold a name, so a nameless commit falls
-	// back to the address and then to a placeholder.
+	// back to the address and then to a placeholder. An ident may carry
+	// an empty name and an empty address, which count as missing.
 	html("<name>");
-	if (info->author)
+	if (info->author && *info->author)
 		xml_txt(info->author);
-	else if (info->author_email)
+	else if (info->author_email && strcmp(info->author_email, "<>"))
 		xml_txt(info->author_email);
 	else
 		html("unknown");
diff --git a/tests/t0301-security.sh b/tests/t0301-security.sh
index f1af8e9..1a5ee44 100755
--- a/tests/t0301-security.sh
+++ b/tests/t0301-security.sh
@@ -373,4 +373,114 @@ test_expect_success 'a quote in a web url cannot break out of the href' '
 	grep "href=.https://example.com/x&#x27;&gt;&lt;script&gt;" tmp
 '
 
+# The classes behind cgit's published advisories, each pinned against the
+# current code: a newline in a file name splitting the headers, a posted
+# length overflowing its buffer, a path climbing out on the dumb transport
+# and the about page, a commit with an empty author, a percent sign with no
+# digits behind it, script in a file name shown by the diff, and shell
+# syntax in a file name handed to a filter.
+test_expect_success 'set up the advisory fixtures' '
+	mkrepo repos/cve 1 &&
+	(
+		cd repos/cve &&
+		printf "x\n" >"$(printf "crlf\r\nX-Injected: 1.txt")" &&
+		printf "x\n" >"<script>alert(1)x.txt" &&
+		printf "x\n" >"\$(touch pwned).c" &&
+		git add -A &&
+		git commit -m names &&
+		tree=$(git rev-parse HEAD^{tree}) &&
+		printf "tree %s\nparent %s\n" "$tree" "$(git rev-parse HEAD)" >raw &&
+		printf "author  <> 1735689600 +0000\ncommitter  <> 1735689600 +0000\n\nempty author\n" >>raw &&
+		cid=$(git hash-object --literally -t commit -w raw) &&
+		git update-ref refs/heads/noname "$cid"
+	) &&
+	mkdir -p readme &&
+	printf "readme text\n" >readme/README &&
+	cat >auth.sh <<-\EOF &&
+	#!/bin/sh
+	case "$1" in
+	authenticate-post)
+		cat >/dev/null
+		printf "Status: 302 Found\nLocation: /\n\n"
+		;;
+	esac
+	exit 1
+	EOF
+	chmod +x auth.sh &&
+	{
+		echo "virtual-root=/" &&
+		echo "cache-size=0" &&
+		echo "auth-filter=exec:$PWD/auth.sh" &&
+		echo "repo.url=cve" &&
+		echo "repo.path=$PWD/repos/cve/.git" &&
+		echo "repo.readme=$PWD/readme/README" &&
+		echo "repo.source-filter=exec:$FILTER_DIRECTORY/dump.sh"
+	} >cverc
+'
+
+cveq() { CGIT_CONFIG="$PWD/cverc" QUERY_STRING="$1" cgit; }
+
+test_expect_success 'a newline in a file name cannot split the headers' '
+	cveq "url=cve/plain/crlf%0d%0aX-Injected:%201.txt" >tmp &&
+	grep "^Status: 200" tmp &&
+	! grep "^X-Injected" tmp &&
+	grep "^Content-Disposition: inline; filename=.crlf\\\\r\\\\nX-Injected: 1.txt.$" tmp
+'
+
+test_expect_success 'a posted length past any buffer is clamped' '
+	echo "username=a&password=b" |
+	CGIT_CONFIG="$PWD/cverc" REQUEST_METHOD=POST CONTENT_LENGTH=99999999999999 \
+		QUERY_STRING="p=login" cgit >tmp &&
+	grep "^Status: 302" tmp
+'
+
+test_expect_success 'the dumb transport refuses a path that climbs out' '
+	cveq "url=cve/objects/../config" >tmp &&
+	grep "^Status: 400" tmp &&
+	! grep "repositoryformatversion" tmp &&
+	cveq "url=cve/objects/info/../../config" >tmp &&
+	grep "^Status: 400" tmp &&
+	! grep "repositoryformatversion" tmp
+'
+
+test_expect_success 'the about page serves nothing above the readme directory' '
+	cveq "url=cve/about/../cverc" >tmp &&
+	grep "^Status: 200" tmp &&
+	! grep "virtual-root" tmp &&
+	cveq "url=cve/about/" >tmp &&
+	grep "readme text" tmp
+'
+
+test_expect_success 'a commit with an empty author renders everywhere' '
+	cveq "url=cve/log/&h=noname" >tmp &&
+	grep ">empty author</a>" tmp &&
+	cveq "url=cve/commit/&h=noname" >tmp &&
+	grep "<div class=.commit-subject.>empty author<" tmp &&
+	cveq "url=cve/atom/&h=noname" >tmp &&
+	grep "<name>unknown</name>" tmp &&
+	! grep "<email></email>" tmp
+'
+
+test_expect_success 'a percent sign without digits behind it is read as itself' '
+	cveq "url=cve/log/&q=%" >tmp &&
+	grep "^Status: 200" tmp &&
+	cveq "url=cve/log/&q=%zz%2" >tmp &&
+	grep "^Status: 200" tmp &&
+	grep "value=.%zz%2." tmp
+'
+
+test_expect_success 'script in a file name is escaped on the diff page' '
+	cveq "url=cve/diff/" >tmp &&
+	! grep "<script>alert" tmp &&
+	grep "&lt;script&gt;alert(1)x.txt" tmp
+'
+
+test_expect_success 'shell syntax in a file name reaches a filter as a plain argument' '
+	cveq "url=cve/tree/%24(touch%20pwned).c" >tmp &&
+	grep "^Status: 200" tmp &&
+	grep "pwned).c" tmp &&
+	! test -e pwned &&
+	! test -e repos/cve/pwned
+'
+
 test_done
-- 
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