From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36425) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xljl0-00022o-VN for qemu-devel@nongnu.org; Tue, 04 Nov 2014 14:27:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xljkl-00080D-Ep for qemu-devel@nongnu.org; Tue, 04 Nov 2014 14:27:10 -0500 From: Alexander Graf Date: Tue, 4 Nov 2014 20:26:38 +0100 Message-Id: <1415129211-9740-21-git-send-email-agraf@suse.de> In-Reply-To: <1415129211-9740-1-git-send-email-agraf@suse.de> References: <1415129211-9740-1-git-send-email-agraf@suse.de> Subject: [Qemu-devel] [PULL 20/33] target-ppc: kvm: Fix memory overflow issue about strncat() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-ppc@nongnu.org Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org, Chen Gang From: Chen Gang strncat() will append additional '\0' to destination buffer, so need additional 1 byte for it, or may cause memory overflow, just like other area within QEMU have done. And can use g_strdup_printf() instead of strncat(), which may be more easier understanding. Signed-off-by: Chen Gang Signed-off-by: Alexander Graf --- target-ppc/kvm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 9c23c6b..6843fa0 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -1782,7 +1782,7 @@ static int kvmppc_find_cpu_dt(char *buf, int buf_len) * format) */ static uint64_t kvmppc_read_int_cpu_dt(const char *propname) { - char buf[PATH_MAX]; + char buf[PATH_MAX], *tmp; union { uint32_t v32; uint64_t v64; @@ -1794,10 +1794,10 @@ static uint64_t kvmppc_read_int_cpu_dt(const char *propname) return -1; } - strncat(buf, "/", sizeof(buf) - strlen(buf)); - strncat(buf, propname, sizeof(buf) - strlen(buf)); + tmp = g_strdup_printf("%s/%s", buf, propname); - f = fopen(buf, "rb"); + f = fopen(tmp, "rb"); + g_free(tmp); if (!f) { return -1; } -- 1.8.1.4