lz4: ensure length does not wrap

commit 206204a upstream. Given some pathologically compressed data, lz4 could possibly decide to wrap a few internal variables, causing unknown things to happen. Catch this before the wrapping happens and abort the decompression. Reported-by: "Don A. Bailey" <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
Davier · Jun 26, 2014 · 5f32449 · 5f32449
1 parent b13fdeb
commit 5f32449
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c
@@ -72,6 +72,8 @@ static int lz4_uncompress(const char *source, char *dest, int osize)
 			len = *ip++;
 			for (; len == 255; length += 255)
 				len = *ip++;
+			if (unlikely(length > (size_t)(length + len)))
+				goto _output_error;
 			length += len;
 		}