From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: [PATCH -next] GRE: Use strlcat() for size checking Date: Wed, 27 Mar 2013 19:48:31 +0100 Message-ID: <1364410111-29418-1-git-send-email-geert@linux-m68k.org> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-next@vger.kernel.org, Geert Uytterhoeven To: Pravin B Shelar , "David S. Miller" Return-path: Sender: linux-next-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On m68k, gcc tries to be smart and turns strncat(name, "%d", 2); into a call to strlen() and a 16-bit store, causing a link failure, as arch/m68k/include/asm/string.h provides strlen() using a macro: ERROR: "strlen" [net/ipv4/ip_tunnel.ko] undefined! Use strlcat() instead to avoid this, which also allows to simplify the check for buffer overflows. Signed-off-by: Geert Uytterhoeven -- Compile-tested only http://kisskb.ellerman.id.au/kisskb/buildresult/8462108/ --- net/ipv4/ip_tunnel.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 9d96b68..8dbe672 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -284,12 +284,11 @@ static struct net_device *__ip_tunnel_create(struct net *net, if (parms->name[0]) strlcpy(name, parms->name, IFNAMSIZ); else { - if (strlen(ops->kind) + 3 >= IFNAMSIZ) { + strlcpy(name, ops->kind, IFNAMSIZ); + if (strlcat(name, "%d", IFNAMSIZ) >= IFNAMSIZ) { err = -E2BIG; goto failed; } - strlcpy(name, ops->kind, IFNAMSIZ); - strncat(name, "%d", 2); } ASSERT_RTNL(); -- 1.7.0.4