Fix compress support and prevent a segfault

1 files changed, 6 insertions, 0 deletions

diff --git a/archival/rpm2cpio.c b/archival/rpm2cpio.c
index e1e93988f..9372dc5e1 100644
--- a/archival/rpm2cpio.c
+++ b/archival/rpm2cpio.c
@@ -70,6 +70,7 @@ extern int rpm2cpio_main(int argc, char **argv)
 {
         struct rpm_lead lead;
         int rpm_fd;
+        unsigned char magic[2];
 
         if (argc == 1) {
                 rpm_fd = fileno(stdin);
@@ -88,6 +89,11 @@ extern int rpm2cpio_main(int argc, char **argv)
 
         /* Skip the main header */
         skip_header(rpm_fd);
+        
+        xread_all(rpm_fd, &magic, 2);
+        if ((magic[0] != 0x1f) || (magic[1] != 0x8b))
+                error_msg_and_die("Invalid gzip magic");
+        }
 
         check_header_gzip(rpm_fd);
         if (inflate(rpm_fd, fileno(stdout)) != 0) {