From 7c5519c12d46ead947d341cbdcbb6fbbe4d4fe1b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= Date: Wed, 23 Sep 2020 12:47:49 +0300 Subject: MDEV-22387: Do not violate __attribute__((nonnull)) Passing a null pointer to a nonnull argument is not only undefined behaviour, but it also grants the compiler the permission to optimize away further checks whether the pointer is null. GCC -O2 at least starting with version 8 may do that, potentially causing SIGSEGV. --- sql/protocol.cc | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'sql/protocol.cc') diff --git a/sql/protocol.cc b/sql/protocol.cc index aa795b9d12a..de6d1b96f76 100644 --- a/sql/protocol.cc +++ b/sql/protocol.cc @@ -1,5 +1,5 @@ /* Copyright (c) 2000, 2012, Oracle and/or its affiliates. - Copyright (c) 2008, 2012, Monty Program Ab + Copyright (c) 2008, 2020, MariaDB Corporation. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -58,7 +58,8 @@ bool Protocol_binary::net_store_data(const uchar *from, size_t length) packet->realloc(packet_length+9+length)) return 1; uchar *to= net_store_length((uchar*) packet->ptr()+packet_length, length); - memcpy(to,from,length); + if (length) + memcpy(to,from,length); packet->length((uint) (to+length-(uchar*) packet->ptr())); return 0; } @@ -715,7 +716,8 @@ void net_send_progress_packet(THD *thd) uchar *net_store_data(uchar *to, const uchar *from, size_t length) { to=net_store_length_fast(to,length); - memcpy(to,from,length); + if (length) + memcpy(to,from,length); return to+length; } -- cgit v1.2.1