From eaf8e725e645818784a42445b4cd62ac35668fe7 Mon Sep 17 00:00:00 2001
From: gkoehler <gkoehler@openbsd.org>
Date: Sat, 11 Nov 2023 02:52:55 +0000
Subject: [PATCH] Ignore -N in "gzip -dN <in.gz" and "zcat -N in.gz"

Have -c override -N, like other gzip implementations.  Before, our -N
(decompress to stored name) overrode -c (cat to stdout) and crashed
with a pledge violation, because the pledge for -c excludes wpath.

Guilherme Janczak reported the pledge violation in July 2022 and
provided a diff to prevent it, along with a regress test.  I rewrote
the diff and expanded the regress.

ok kn@ millert@
---
 regress/usr.bin/gzip/Makefile | 27 +++++++++++++++++++++++++--
 usr.bin/compress/main.c       |  6 +++---
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/regress/usr.bin/gzip/Makefile b/regress/usr.bin/gzip/Makefile
index 2777447a75c..efbf7afe5b9 100644
--- a/regress/usr.bin/gzip/Makefile
+++ b/regress/usr.bin/gzip/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.2 2017/06/22 16:10:34 bluhm Exp $
+# $OpenBSD: Makefile,v 1.3 2023/11/11 02:52:55 gkoehler Exp $
 
 # Copyright (c) 2008 Marco Pfatschbacher <mpf@openbsd.org>
 # Copyright (c) 2017 Alexander Bluhm <bluhm@openbsd.org>
@@ -15,7 +15,7 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-CLEANFILES=	*.gz rc rcmotd multi owner perm
+CLEANFILES=	*.gz rc rcmotd multi owner out perm
 
 # Test if gzip(1) detects truncated or corrupted files
 
@@ -96,6 +96,29 @@ run-regress-multi:
 	cat /etc/rc /etc/motd >rcmotd
 	diff -up rcmotd multi
 
+# Test -N
+
+REGRESS_TARGETS+=	run-regress-name
+run-regress-name:
+	@echo "\n==== $@ ===="
+	# check gunzip -N
+	gzip -c /etc/rc >in.gz
+	rm -f rc
+	gunzip -N in.gz
+	diff -up /etc/rc rc
+	# check that -N works with -l
+	gzip -c /etc/rc >in.gz
+	gzip -lN in.gz | grep -q ' rc$$'
+	gzip -lN <in.gz | grep -q ' rc$$'
+	# check that stdout ignores -N
+	rm -f out
+	gzip -dN <in.gz >out
+	diff -up /etc/rc out
+	# check that zcat ignores -N
+	rm -f out
+	zcat -N in.gz >out
+	diff -up /etc/rc out
+
 # Test permissions
 
 REGRESS_TARGETS+=	run-regress-perm-zip
diff --git a/usr.bin/compress/main.c b/usr.bin/compress/main.c
index 834f3bd90d3..e6f4f8f4b99 100644
--- a/usr.bin/compress/main.c
+++ b/usr.bin/compress/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.105 2023/08/11 04:45:05 guenther Exp $	*/
+/*	$OpenBSD: main.c,v 1.106 2023/11/11 02:52:55 gkoehler Exp $	*/
 
 /*
  * Copyright (c) 1992, 1993
@@ -699,7 +699,8 @@ dodecompress(const char *in, char *out, struct stat *sb)
 		close (ifd);
 		return (FAILURE);
 	}
-	if (storename && oldname[0] != '\0') {
+	/* Ignore -N when decompressing to stdout. */
+	if (storename && (!cat || list) && oldname[0] != '\0') {
 		const char *oldbase = basename(oldname);
 		char *cp = strrchr(out, '/');
 		if (cp != NULL) {
@@ -707,7 +708,6 @@ dodecompress(const char *in, char *out, struct stat *sb)
 			strlcat(out, oldbase, PATH_MAX);
 		} else
 			strlcpy(out, oldbase, PATH_MAX);
-		cat = 0;			/* XXX should -c override? */
 	}
 
 	if (testmode) {
-- 
2.20.1