From 75f32f047cc380bdb648faf3ee277f7dc3cdd007 Mon Sep 17 00:00:00 2001 From: Zbigniew Jędrzejewski-Szmek Date: Mon, 1 Feb 2016 21:57:41 -0500 Subject: Add memcpy_safe MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ISO/IEC 9899:1999 §7.21.1/2 says: Where an argument declared as size_t n specifies the length of the array for a function, n can have the value zero on a call to that function. Unless explicitly stated otherwise in the description of a particular function in this subclause, pointer arguments on such a call shall still have valid values, as described in 7.1.4. In base64_append_width memcpy was called as memcpy(x, NULL, 0). GCC 4.9 started making use of this and assumes This worked fine under -O0, but does something strange under -O3. This patch fixes a bug in base64_append_width(), fixes a possible bug in journal_file_append_entry_internal(), and makes use of the new function to simplify the code in other places. --- src/libsystemd-network/dhcp6-option.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'src/libsystemd-network/dhcp6-option.c') diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c index 6050851858..e858e14d97 100644 --- a/src/libsystemd-network/dhcp6-option.c +++ b/src/libsystemd-network/dhcp6-option.c @@ -73,8 +73,7 @@ int dhcp6_option_append(uint8_t **buf, size_t *buflen, uint16_t code, if (r < 0) return r; - if (optval) - memcpy(*buf, optval, optlen); + memcpy_safe(*buf, optval, optlen); *buf += optlen; *buflen -= optlen; -- cgit v1.2.3-54-g00ecf