1 files changed, 10 insertions, 1 deletions

diff --git a/archival/bbunzip.c b/archival/bbunzip.c
index b243afb2e..c1259ac46 100644
--- a/archival/bbunzip.c
+++ b/archival/bbunzip.c
@@ -373,12 +373,21 @@ int unlzma_main(int argc UNUSED_PARAM, char **argv)
 static
 IF_DESKTOP(long long) int FAST_FUNC unpack_unxz(unpack_info_t *info UNUSED_PARAM)
 {
+        struct {
+                uint32_t v1;
+                uint16_t v2;
+        } magic;
+        xread(STDIN_FILENO, &magic, 6);
+        if (magic.v1 != XZ_MAGIC1a || magic.v2 != XZ_MAGIC2a) {
+                bb_error_msg("invalid magic");
+                return -1;
+        }
         return unpack_xz_stream(STDIN_FILENO, STDOUT_FILENO);
 }
 int unxz_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int unxz_main(int argc UNUSED_PARAM, char **argv)
 {
-        int opts = getopt32(argv, "cfvdt");
+        IF_XZ(int opts =) getopt32(argv, "cfvdt");
 # if ENABLE_XZ
         /* xz without -d or -t? */
         if (applet_name[2] == '\0' && !(opts & (OPT_DECOMPRESS|OPT_TEST)))