Patchwork netlabel: improve domain mapping validation

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Submitter Paul Moore
Date May 17, 2013, 7:08 p.m.
Message ID <20130517190850.11148.51057.stgit@localhost>
Download mbox | patch
Permalink /patch/244690/
State Accepted
Delegated to: David Miller
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Comments

Paul Moore - May 17, 2013, 7:08 p.m.
The net/netlabel/netlabel_domainhash.c:netlbl_domhsh_add() function
does not properly validate new domain hash entries resulting in
potential problems when an administrator attempts to add an invalid
entry.  One such problem, as reported by Vlad Halilov, is a kernel
BUG (found in netlabel_domainhash.c:netlbl_domhsh_audit_add()) when
adding an IPv6 outbound mapping with a CIPSO configuration.

This patch corrects this problem by adding the necessary validation
code to netlbl_domhsh_add() via the newly created
netlbl_domhsh_validate() function.

Ideally this patch should also be pushed to the currently active
-stable trees.

Reported-by: Vlad Halilov <vlad.halilov@gmail.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
---
 net/netlabel/netlabel_domainhash.c |   69 ++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)


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Sergei Shtylyov - May 17, 2013, 7:23 p.m.
Hello.

On 05/17/2013 11:08 PM, Paul Moore wrote:

> The net/netlabel/netlabel_domainhash.c:netlbl_domhsh_add() function
> does not properly validate new domain hash entries resulting in
> potential problems when an administrator attempts to add an invalid
> entry.  One such problem, as reported by Vlad Halilov, is a kernel
> BUG (found in netlabel_domainhash.c:netlbl_domhsh_audit_add()) when
> adding an IPv6 outbound mapping with a CIPSO configuration.
>
> This patch corrects this problem by adding the necessary validation
> code to netlbl_domhsh_add() via the newly created
> netlbl_domhsh_validate() function.
>
> Ideally this patch should also be pushed to the currently active
> -stable trees.
>
> Reported-by: Vlad Halilov <vlad.halilov@gmail.com>
> Signed-off-by: Paul Moore <pmoore@redhat.com>
> ---
>   net/netlabel/netlabel_domainhash.c |   69 ++++++++++++++++++++++++++++++++++++
>   1 file changed, 69 insertions(+)
>
> diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c
> index d8d4243..6bb1d42 100644
> --- a/net/netlabel/netlabel_domainhash.c
> +++ b/net/netlabel/netlabel_domainhash.c
> @@ -245,6 +245,71 @@ static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
>   	}
>   }
>   
> +/**
> + * netlbl_domhsh_validate - Validate a new domain mapping entry
> + * @entry: the entry to validate
> + *
> + * This function validates the new domain mapping entry to ensure that it is
> + * a valid entry.  Returns zero on success, negative values on failure.
> + *
> + */
> +static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
> +{
> +	struct netlbl_af4list *iter4;
> +	struct netlbl_domaddr4_map *map4;
> +#if IS_ENABLED(CONFIG_IPV6)
> +	struct netlbl_af6list *iter6;
> +	struct netlbl_domaddr6_map *map6;
> +#endif /* IPv6 */
> +
> +	if (entry == NULL)
> +		return -EINVAL;
> +
> +	switch (entry->type) {
> +	case NETLBL_NLTYPE_UNLABELED:
> +		if (entry->type_def.cipsov4 != NULL ||
> +		    entry->type_def.addrsel != NULL)
> +			return -EINVAL;
> +		break;
> +	case NETLBL_NLTYPE_CIPSOV4:
> +		if (entry->type_def.cipsov4 == NULL)
> +			return -EINVAL;
> +		break;
> +	case NETLBL_NLTYPE_ADDRSELECT:
> +		netlbl_af4list_foreach(iter4, &entry->type_def.addrsel->list4) {
> +			map4 = netlbl_domhsh_addr4_entry(iter4);
> +			switch (map4->type) {
> +			case NETLBL_NLTYPE_UNLABELED:
> +				if (map4->type_def.cipsov4 != NULL)
> +					return -EINVAL;
> +				break;
> +			case NETLBL_NLTYPE_CIPSOV4:
> +				if (map4->type_def.cipsov4 == NULL)
> +					return -EINVAL;
> +				break;
> +			default:
> +				return -EINVAL;
> +			}
> +		}
> +#if IS_ENABLED(CONFIG_IPV6)

   Why not:

         if (IS_ENABLED(CONFIG_IPV6))

    #if's in the function body are frowned upon.

> +		netlbl_af6list_foreach(iter6, &entry->type_def.addrsel->list6) {
> +			map6 = netlbl_domhsh_addr6_entry(iter6);
> +			switch (map6->type) {
> +			case NETLBL_NLTYPE_UNLABELED:
> +				break;
> +			default:
> +				return -EINVAL;
> +			}
> +		}
> +#endif /* IPv6 */
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +

WBR, Sergei

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Paul Moore - May 17, 2013, 7:37 p.m.
On Friday, May 17, 2013 11:23:03 PM Sergei Shtylyov wrote:
> Hello.
> 
> On 05/17/2013 11:08 PM, Paul Moore wrote:
> > The net/netlabel/netlabel_domainhash.c:netlbl_domhsh_add() function
> > does not properly validate new domain hash entries resulting in
> > potential problems when an administrator attempts to add an invalid
> > entry.  One such problem, as reported by Vlad Halilov, is a kernel
> > BUG (found in netlabel_domainhash.c:netlbl_domhsh_audit_add()) when
> > adding an IPv6 outbound mapping with a CIPSO configuration.
> > 
> > This patch corrects this problem by adding the necessary validation
> > code to netlbl_domhsh_add() via the newly created
> > netlbl_domhsh_validate() function.
> > 
> > Ideally this patch should also be pushed to the currently active
> > -stable trees.
> > 
> > Reported-by: Vlad Halilov <vlad.halilov@gmail.com>
> > Signed-off-by: Paul Moore <pmoore@redhat.com>

...

> > +#if IS_ENABLED(CONFIG_IPV6)
> 
>    Why not:
> 
>          if (IS_ENABLED(CONFIG_IPV6))
> 
>     #if's in the function body are frowned upon.

The dependent functions/types are not defined when !IS_ENABLED(CONFIG_IPV6); 
please look at the rest of the NetLabel code (net/netlabel).

Perhaps we can do some work to fixup some of that in the future, but that 
shouldn't hold up this fix.
 
> > +		netlbl_af6list_foreach(iter6, &entry->type_def.addrsel->list6) {
> > +			map6 = netlbl_domhsh_addr6_entry(iter6);
> > +			switch (map6->type) {
> > +			case NETLBL_NLTYPE_UNLABELED:
> > +				break;
> > +			default:
> > +				return -EINVAL;
> > +			}
> > +		}
> > +#endif /* IPv6 */
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	return 0;
> > +}
Sergei Shtylyov - May 17, 2013, 9:47 p.m.
On 05/17/2013 11:37 PM, Paul Moore wrote:

>>> The net/netlabel/netlabel_domainhash.c:netlbl_domhsh_add() function
>>> does not properly validate new domain hash entries resulting in
>>> potential problems when an administrator attempts to add an invalid
>>> entry.  One such problem, as reported by Vlad Halilov, is a kernel
>>> BUG (found in netlabel_domainhash.c:netlbl_domhsh_audit_add()) when
>>> adding an IPv6 outbound mapping with a CIPSO configuration.
>>>
>>> This patch corrects this problem by adding the necessary validation
>>> code to netlbl_domhsh_add() via the newly created
>>> netlbl_domhsh_validate() function.
>>>
>>> Ideally this patch should also be pushed to the currently active
>>> -stable trees.
>>>
>>> Reported-by: Vlad Halilov <vlad.halilov@gmail.com>
>>> Signed-off-by: Paul Moore <pmoore@redhat.com>
> ...
>
>>> +#if IS_ENABLED(CONFIG_IPV6)
>>     Why not:
>>
>>           if (IS_ENABLED(CONFIG_IPV6))
>>
>>      #if's in the function body are frowned upon.
> The dependent functions/types are not defined when !IS_ENABLED(CONFIG_IPV6);
> please look at the rest of the NetLabel code (net/netlabel).

     Sorry, didn't think about declarations.

> Perhaps we can do some work to fixup some of that in the future, but that
> shouldn't hold up this fix.

     Perhaps factoring out the #ifdef'ed code into a separate function 
would help
if at all possible.

WBR, Sergei

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David Miller - May 19, 2013, 9:50 p.m.
From: Paul Moore <pmoore@redhat.com>
Date: Fri, 17 May 2013 15:08:50 -0400

> The net/netlabel/netlabel_domainhash.c:netlbl_domhsh_add() function
> does not properly validate new domain hash entries resulting in
> potential problems when an administrator attempts to add an invalid
> entry.  One such problem, as reported by Vlad Halilov, is a kernel
> BUG (found in netlabel_domainhash.c:netlbl_domhsh_audit_add()) when
> adding an IPv6 outbound mapping with a CIPSO configuration.
> 
> This patch corrects this problem by adding the necessary validation
> code to netlbl_domhsh_add() via the newly created
> netlbl_domhsh_validate() function.
> 
> Ideally this patch should also be pushed to the currently active
> -stable trees.
> 
> Reported-by: Vlad Halilov <vlad.halilov@gmail.com>
> Signed-off-by: Paul Moore <pmoore@redhat.com>

Applied and queued up for -stable, thanks.
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Patch

diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c
index d8d4243..6bb1d42 100644
--- a/net/netlabel/netlabel_domainhash.c
+++ b/net/netlabel/netlabel_domainhash.c
@@ -245,6 +245,71 @@  static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
 	}
 }
 
+/**
+ * netlbl_domhsh_validate - Validate a new domain mapping entry
+ * @entry: the entry to validate
+ *
+ * This function validates the new domain mapping entry to ensure that it is
+ * a valid entry.  Returns zero on success, negative values on failure.
+ *
+ */
+static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
+{
+	struct netlbl_af4list *iter4;
+	struct netlbl_domaddr4_map *map4;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct netlbl_af6list *iter6;
+	struct netlbl_domaddr6_map *map6;
+#endif /* IPv6 */
+
+	if (entry == NULL)
+		return -EINVAL;
+
+	switch (entry->type) {
+	case NETLBL_NLTYPE_UNLABELED:
+		if (entry->type_def.cipsov4 != NULL ||
+		    entry->type_def.addrsel != NULL)
+			return -EINVAL;
+		break;
+	case NETLBL_NLTYPE_CIPSOV4:
+		if (entry->type_def.cipsov4 == NULL)
+			return -EINVAL;
+		break;
+	case NETLBL_NLTYPE_ADDRSELECT:
+		netlbl_af4list_foreach(iter4, &entry->type_def.addrsel->list4) {
+			map4 = netlbl_domhsh_addr4_entry(iter4);
+			switch (map4->type) {
+			case NETLBL_NLTYPE_UNLABELED:
+				if (map4->type_def.cipsov4 != NULL)
+					return -EINVAL;
+				break;
+			case NETLBL_NLTYPE_CIPSOV4:
+				if (map4->type_def.cipsov4 == NULL)
+					return -EINVAL;
+				break;
+			default:
+				return -EINVAL;
+			}
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		netlbl_af6list_foreach(iter6, &entry->type_def.addrsel->list6) {
+			map6 = netlbl_domhsh_addr6_entry(iter6);
+			switch (map6->type) {
+			case NETLBL_NLTYPE_UNLABELED:
+				break;
+			default:
+				return -EINVAL;
+			}
+		}
+#endif /* IPv6 */
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /*
  * Domain Hash Table Functions
  */
@@ -311,6 +376,10 @@  int netlbl_domhsh_add(struct netlbl_dom_map *entry,
 	struct netlbl_af6list *tmp6;
 #endif /* IPv6 */
 
+	ret_val = netlbl_domhsh_validate(entry);
+	if (ret_val != 0)
+		return ret_val;
+
 	/* XXX - we can remove this RCU read lock as the spinlock protects the
 	 *       entire function, but before we do we need to fixup the
 	 *       netlbl_af[4,6]list RCU functions to do "the right thing" with