[PATCH] Fix buffer overflow in ce_flush().

From: Qingning Huo <qhuo@mayhq.co.uk>
Date: Sep 11, 2005, 13:27 UTC
Message-ID: <20050911132747.GA26401@mayhq.zapto.org>

Fix buffer overflow in ce_flush().

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

---

 read-cache.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

ca84fa808ba3a314d3d9ea5cfb7b8c2462249ca3

diff --git a/read-cache.c b/read-cache.c
--- a/read-cache.c
+++ b/read-cache.c
@@ -462,6 +462,13 @@ static int ce_flush(SHA_CTX *context, in
 		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;