From 77c77f0a1b9f15b869ca3342186dfbedd1119d0e Mon Sep 17 00:00:00 2001 From: Matt Caswell Date: Mon, 2 Mar 2015 09:27:10 +0000 Subject: [PATCH] Multiblock corrupted pointer fix OpenSSL 1.0.2 introduced the "multiblock" performance improvement. This feature only applies on 64 bit x86 architecture platforms that support AES NI instructions. A defect in the implementation of "multiblock" can cause OpenSSL's internal write buffer to become incorrectly set to NULL when using non-blocking IO. Typically, when the user application is using a socket BIO for writing, this will only result in a failed connection. However if some other BIO is used then it is likely that a segmentation fault will be triggered, thus enabling a potential DoS attack. CVE-2015-0290 Reviewed-by: Richard Levitte Reviewed-by: Andy Polyakov --- ssl/s3_pkt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c index 4e6a41bd58..221ae039e9 100644 --- a/ssl/s3_pkt.c +++ b/ssl/s3_pkt.c @@ -785,7 +785,7 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) i = ssl3_write_pending(s, type, &buf[tot], nw); if (i <= 0) { - if (i < 0) { + if (i < 0 && (!s->wbio || !BIO_should_retry(s->wbio))) { OPENSSL_free(wb->buf); wb->buf = NULL; } -- 2.25.1