[PATCH 3.2 110/125] netlink: rate-limit leftover bytes warning and print process name

Ben Hutchings
2014-07-08T19:46:57Z

From: Michal Schmidt <mschmidt@redhat.com>

[ Upstream commit bfc5184b69cf9eeb286137640351c650c27f118a ]

Any process is able to send netlink messages with leftover bytes.
Make the warning rate-limited to prevent too much log spam.

The warning is supposed to help find userspace bugs, so print the
triggering command name to implicate the buggy program.

[v2: Use pr_warn_ratelimited instead of printk_ratelimited.]

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
lib/nlattr.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -12,6 +12,7 @@
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/string.h>
+#include <linux/ratelimit.h>
#include <linux/types.h>
#include <net/netlink.h>

@@ -197,8 +198,8 @@ int nla_parse(struct nlattr **tb, int ma
}

if (unlikely(rem > 0))
- printk(KERN_WARNING "netlink: %d bytes leftover after parsing "
- "attributes.\n", rem);
+ pr_warn_ratelimited("netlink: %d bytes leftover after parsing attributes in process `%s'.\n",
+ rem, current->comm);

err = 0;