Do something useful for directories by setting the mask to 0.

This avoids buffer overflows by always truncating the window correctly.

Reported-By: OSS-Fuzz issue 11011

diff --git a/libarchive/archive_read_support_format_rar5.c b/libarchive/archive_read_support_format_rar5.c
index 31f9dd530e122b7f61444364c6f25b5ad3b7f1d0..99d8176818cca15fdd7d50e97a725e0f68bc8007 100644 (file)
--- a/libarchive/archive_read_support_format_rar5.c
+++ b/libarchive/archive_read_support_format_rar5.c
@@ -1836,7 +1836,10 @@ static int rar5_read_header(struct archive_read *a,
 
 static void init_unpack(struct rar5* rar) {
     rar->file.calculated_crc32 = 0;
-    rar->cstate.window_mask = rar->cstate.window_size - 1;
+    if (rar->cstate.window_size)
+        rar->cstate.window_mask = rar->cstate.window_size - 1;
+    else
+        rar->cstate.window_mask = 0;
 
     if(rar->cstate.window_buf)
         free(rar->cstate.window_buf);