From: Dave Reisner <dreisner@archlinux.org>
Date: Mon, 7 May 2012 23:41:41 +0000 (-0400)
Subject: libkmod-file: gracefully handle errors from zlib
X-Git-Tag: v9~49
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c7d5a60d3df735a3816bbc1ff1b416a803a4f7a6;p=thirdparty%2Fkmod.git

libkmod-file: gracefully handle errors from zlib

zlib won't necessarily set the system errno, and this is particularly
evident on corrupted data (which results in a double free). Use zlib's
gzerror to detect the failure, returning a generic EINVAL when zlib
doesn't provide us with an errno.
---

diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
index 46ad8d96..8beb7e34 100644
--- a/libkmod/libkmod-file.c
+++ b/libkmod/libkmod-file.c
@@ -199,7 +199,13 @@ static int load_zlib(struct kmod_file *file)
 		if (r == 0)
 			break;
 		else if (r < 0) {
-			err = -errno;
+			int gzerr;
+			const char *gz_errmsg = gzerror(file->gzf, &gzerr);
+
+			ERR(file->ctx, "gzip: %s\n", gz_errmsg);
+
+			/* gzip might not set errno here */
+			err = gzerr == Z_ERRNO ? -errno : -EINVAL;
 			goto error;
 		}
 		did += r;