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* [PATCH] netns: more input validation
@ 2017-07-25 13:30 Matteo Croce
  2017-07-25 13:47 ` David Laight
  2017-07-27 18:26 ` Stephen Hemminger
  0 siblings, 2 replies; 4+ messages in thread
From: Matteo Croce @ 2017-07-25 13:30 UTC (permalink / raw)
  To: netdev; +Cc: Stephen Hemminger

ip netns accepts invalid input as namespace name like an empty string or a
string longer than the maximum file name length.
Check that the netns name is not empty and less than or equal to NAME_MAX.

Signed-off-by: Matteo Croce <mcroce@redhat.com>
---
 ip/ipnetns.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index 42549944..198e9de8 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -768,7 +768,8 @@ static int netns_monitor(int argc, char **argv)
 
 static int invalid_name(const char *name)
 {
-	return strchr(name, '/') || !strcmp(name, ".") || !strcmp(name, "..");
+	return !*name || strlen(name) > NAME_MAX ||
+		strchr(name, '/') || !strcmp(name, ".") || !strcmp(name, "..");
 }
 
 int do_netns(int argc, char **argv)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* RE: [PATCH] netns: more input validation
  2017-07-25 13:30 [PATCH] netns: more input validation Matteo Croce
@ 2017-07-25 13:47 ` David Laight
  2017-07-25 14:08   ` Matteo Croce
  2017-07-27 18:26 ` Stephen Hemminger
  1 sibling, 1 reply; 4+ messages in thread
From: David Laight @ 2017-07-25 13:47 UTC (permalink / raw)
  To: 'Matteo Croce', netdev@vger.kernel.org; +Cc: Stephen Hemminger

From: Matteo Croce
> Sent: 25 July 2017 14:31
> ip netns accepts invalid input as namespace name like an empty string or a
> string longer than the maximum file name length.
> Check that the netns name is not empty and less than or equal to NAME_MAX.
> 
> Signed-off-by: Matteo Croce <mcroce@redhat.com>
> ---
>  ip/ipnetns.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/ip/ipnetns.c b/ip/ipnetns.c
> index 42549944..198e9de8 100644
> --- a/ip/ipnetns.c
> +++ b/ip/ipnetns.c
> @@ -768,7 +768,8 @@ static int netns_monitor(int argc, char **argv)
> 
>  static int invalid_name(const char *name)
>  {
> -	return strchr(name, '/') || !strcmp(name, ".") || !strcmp(name, "..");
> +	return !*name || strlen(name) > NAME_MAX ||
> +		strchr(name, '/') || !strcmp(name, ".") || !strcmp(name, "..");

Think I'd check:
	!name[0] || !memchr(name, 0, NAME_MAX) || strchr(name, '/') ||
		(name[0] == '.' && (!name[1] || (name[1] == '.' && !name[2])))

	David

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] netns: more input validation
  2017-07-25 13:47 ` David Laight
@ 2017-07-25 14:08   ` Matteo Croce
  0 siblings, 0 replies; 4+ messages in thread
From: Matteo Croce @ 2017-07-25 14:08 UTC (permalink / raw)
  To: David Laight, netdev@vger.kernel.org; +Cc: Stephen Hemminger

Il giorno mar, 25/07/2017 alle 13.47 +0000, David Laight ha scritto:
> Think I'd check:
> 	!name[0] || !memchr(name, 0, NAME_MAX) || strchr(name, '/') ||
> 		(name[0] == '.' && (!name[1] || (name[1] == '.' &&
> !name[2])))
> 
> 	David

Nice optimization, but as strchr() and strcmp() are builtin functions,
at least in GCC, I don't know if there is any real advantage.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] netns: more input validation
  2017-07-25 13:30 [PATCH] netns: more input validation Matteo Croce
  2017-07-25 13:47 ` David Laight
@ 2017-07-27 18:26 ` Stephen Hemminger
  1 sibling, 0 replies; 4+ messages in thread
From: Stephen Hemminger @ 2017-07-27 18:26 UTC (permalink / raw)
  To: Matteo Croce; +Cc: netdev

On Tue, 25 Jul 2017 15:30:31 +0200
Matteo Croce <mcroce@redhat.com> wrote:

> ip netns accepts invalid input as namespace name like an empty string or a
> string longer than the maximum file name length.
> Check that the netns name is not empty and less than or equal to NAME_MAX.
> 
> Signed-off-by: Matteo Croce <mcroce@redhat.com>

Sure, applied.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2017-07-27 18:26 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2017-07-25 13:30 [PATCH] netns: more input validation Matteo Croce
2017-07-25 13:47 ` David Laight
2017-07-25 14:08   ` Matteo Croce
2017-07-27 18:26 ` Stephen Hemminger

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