[PATCH AUTOSEL 5.0 095/262] veth: Fix -Wformat-truncation

Sasha Levin
2019-03-27T18:05:06Z

From: Florian Fainelli <f.fainelli@gmail.com>

[ Upstream commit abdf47aab4123ece48877cab4153db44fe4dc340 ]

Provide a precision hint to snprintf() in order to eliminate a
-Wformat-truncation warning provided below. A maximum of 11 characters
is allowed to reach a maximum of 32 - 1 characters given a possible
maximum value of queues using up to UINT_MAX which occupies 10
characters. Incidentally 11 is the number of characters for
"xdp_packets" which is the largest string we append.

drivers/net/veth.c: In function 'veth_get_strings':
drivers/net/veth.c:118:47: warning: '%s' directive output may be
truncated writing up to 31 bytes into a region of size between 12 and 21
[-Wformat-truncation=]
snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
^~
drivers/net/veth.c:118:5: note: 'snprintf' output between 12 and 52
bytes into a destination of size 32
snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
i, veth_rq_stats_desc[j].desc);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/veth.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index f412ea1cef18..b203d1867959 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -115,7 +115,8 @@ static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
p += sizeof(ethtool_stats_keys);
for (i = 0; i < dev->real_num_rx_queues; i++) {
for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
- snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
+ snprintf(p, ETH_GSTRING_LEN,
+ "rx_queue_%u_%.11s",
i, veth_rq_stats_desc[j].desc);
p += ETH_GSTRING_LEN;
}
--
2.19.1