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Subject[PATCH -next] GRE: Use strlcat() for size checking
Date
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 <geert@linux-m68k.org>
--
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


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