[PATCH] Fix buffer overflow in ce_flush().

Add a check before appending SHA1 signature to write_buffer,
flush it first if necessary.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/read-cache.c b/read-cache.c
index ced5973..6eff4c8 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -462,6 +462,13 @@ static int ce_flush(SHA_CTX *context, int fd)
                SHA1_Update(context, write_buffer, left);
        }
 
+       /* Flush first if not enough space for SHA1 signature */
+       if (left + 20 > WRITE_BUFFER_SIZE) {
+               if (write(fd, write_buffer, left) != left)
+                       return -1;
+               left = 0;
+       }
+
        /* Append the SHA1 signature at the end */
        SHA1_Final(write_buffer + left, context);
        left += 20;