[PATCH] selinux: clean up avc node cache when disabling selinux

[PATCH] selinux: clean up avc node cache when disabling selinux

[Thomas Liu]

Added a call to free the avc_node_cache when inside selinux_disable because
it should not waste resources allocated during avc_init if SELinux is disabled
and the cache will never be used.

Signed-off-by: Thomas Liu <tliu@redhat.com>
---
diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/avc.c kernel/security/selinux/avc.c
--- kernel-vanilla/security/selinux/avc.c	2009-06-24 15:51:29.227941185 -0400
+++ kernel/security/selinux/avc.c	2009-06-24 17:46:30.292941891 -0400
@@ -970,3 +970,9 @@ u32 avc_policy_seqno(void)
 {
 	return avc_cache.latest_notif;
 }
+
+void avc_disable(void)
+{
+	if (avc_node_cachep)
+		kmem_cache_destroy(avc_node_cachep);
+}
diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/hooks.c kernel/security/selinux/hooks.c
--- kernel-vanilla/security/selinux/hooks.c	2009-06-24 15:51:29.229939614 -0400
+++ kernel/security/selinux/hooks.c	2009-06-24 16:13:14.828941026 -0400
@@ -5678,6 +5678,9 @@ int selinux_disable(void)
 	selinux_disabled = 1;
 	selinux_enabled = 0;
 
+	/* Try to destroy the avc node cache */
+	avc_node_cache_free();
+
 	/* Reset security_ops to the secondary module, dummy or capability. */
 	security_ops = secondary_ops;
 
diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/include/avc.h kernel/security/selinux/include/avc.h
--- kernel-vanilla/security/selinux/include/avc.h	2009-06-24 15:51:29.230938689 -0400
+++ kernel/security/selinux/include/avc.h	2009-06-24 17:46:42.540941620 -0400
@@ -134,6 +134,9 @@ void avc_dump_av(struct audit_buffer *ab
 int avc_get_hash_stats(char *page);
 extern unsigned int avc_cache_threshold;
 
+/* Attempt to free avc node cache */
+void avc_disable(void);
+
 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
 DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
 #endif


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Re: [PATCH] selinux: clean up avc node cache when disabling selinux

[Eric Paris]

On Wed, 2009-06-24 at 17:54 -0400, Thomas Liu wrote:
> Added a call to free the avc_node_cache when inside selinux_disable because
> it should not waste resources allocated during avc_init if SELinux is disabled
> and the cache will never be used.
> 
> Signed-off-by: Thomas Liu <tliu@redhat.com>
> ---
> diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/avc.c kernel/security/selinux/avc.c
> --- kernel-vanilla/security/selinux/avc.c	2009-06-24 15:51:29.227941185 -0400
> +++ kernel/security/selinux/avc.c	2009-06-24 17:46:30.292941891 -0400
> @@ -970,3 +970,9 @@ u32 avc_policy_seqno(void)
>  {
>  	return avc_cache.latest_notif;
>  }
> +
> +void avc_disable(void)
> +{
> +	if (avc_node_cachep)
> +		kmem_cache_destroy(avc_node_cachep);
> +}
> diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/hooks.c kernel/security/selinux/hooks.c
> --- kernel-vanilla/security/selinux/hooks.c	2009-06-24 15:51:29.229939614 -0400
> +++ kernel/security/selinux/hooks.c	2009-06-24 16:13:14.828941026 -0400
> @@ -5678,6 +5678,9 @@ int selinux_disable(void)
>  	selinux_disabled = 1;
>  	selinux_enabled = 0;
>  
> +	/* Try to destroy the avc node cache */
> +	avc_node_cache_free();

whoops!  did you compile it?

> +
>  	/* Reset security_ops to the secondary module, dummy or capability. */
>  	security_ops = secondary_ops;
>  
> diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/include/avc.h kernel/security/selinux/include/avc.h
> --- kernel-vanilla/security/selinux/include/avc.h	2009-06-24 15:51:29.230938689 -0400
> +++ kernel/security/selinux/include/avc.h	2009-06-24 17:46:42.540941620 -0400
> @@ -134,6 +134,9 @@ void avc_dump_av(struct audit_buffer *ab
>  int avc_get_hash_stats(char *page);
>  extern unsigned int avc_cache_threshold;
>  
> +/* Attempt to free avc node cache */
> +void avc_disable(void);
> +
>  #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
>  DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
>  #endif
> 


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[PATCH -v2] selinux: clean up avc node cache when disabling selinux

[Thomas Liu]

Added a call to free the avc_node_cache when inside selinux_disable because
it should not waste resources allocated during avc_init if SELinux is disabled
and the cache will never be used.

Signed-off-by: Thomas Liu <tliu@redhat.com>
---
diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/avc.c kernel/security/selinux/avc.c
--- kernel-vanilla/security/selinux/avc.c	2009-06-24 15:51:29.227941185 -0400
+++ kernel/security/selinux/avc.c	2009-06-24 17:46:30.292941891 -0400
@@ -970,3 +970,9 @@ u32 avc_policy_seqno(void)
 {
 	return avc_cache.latest_notif;
 }
+
+void avc_disable(void)
+{
+	if (avc_node_cachep)
+		kmem_cache_destroy(avc_node_cachep);
+}
diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/hooks.c kernel/security/selinux/hooks.c
--- kernel-vanilla/security/selinux/hooks.c	2009-06-24 15:51:29.229939614 -0400
+++ kernel/security/selinux/hooks.c	2009-06-24 16:13:14.828941026 -0400
@@ -5678,6 +5678,9 @@ int selinux_disable(void)
 	selinux_disabled = 1;
 	selinux_enabled = 0;
 
+	/* Try to destroy the avc node cache */
+	avc_disable();
+
 	/* Reset security_ops to the secondary module, dummy or capability. */
 	security_ops = secondary_ops;
 
diff -uprN -X kernel-vanilla/Documentation/dontdiff kernel-vanilla/security/selinux/include/avc.h kernel/security/selinux/include/avc.h
--- kernel-vanilla/security/selinux/include/avc.h	2009-06-24 15:51:29.230938689 -0400
+++ kernel/security/selinux/include/avc.h	2009-06-24 17:46:42.540941620 -0400
@@ -134,6 +134,9 @@ void avc_dump_av(struct audit_buffer *ab
 int avc_get_hash_stats(char *page);
 extern unsigned int avc_cache_threshold;
 
+/* Attempt to free avc node cache */
+void avc_disable(void);
+
 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
 DECLARE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
 #endif



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Re: [PATCH -v2] selinux: clean up avc node cache when disabling selinux

[Eric Paris]

On Wed, 2009-06-24 at 17:58 -0400, Thomas Liu wrote:
> Added a call to free the avc_node_cache when inside selinux_disable because
> it should not waste resources allocated during avc_init if SELinux is disabled
> and the cache will never be used.
> 
> Signed-off-by: Thomas Liu <tliu@redhat.com>

Acked-by: Eric Paris <eparis@redhat.com>


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Re: [PATCH -v2] selinux: clean up avc node cache when disabling selinux

[James Morris]

On Wed, 24 Jun 2009, Thomas Liu wrote:

> Added a call to free the avc_node_cache when inside selinux_disable because
> it should not waste resources allocated during avc_init if SELinux is disabled
> and the cache will never be used.
> 
> Signed-off-by: Thomas Liu <tliu@redhat.com>


Applied to
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6#next


-- 
James Morris
<jmorris@namei.org>

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