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From: David Howells <dhowells@redhat.com>
To: Trond.Myklebust@netapp.com, chuck.lever@oracle.com,
	casey@schaufler-ca.com
Cc: nfsv4@linux-nfs.org, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, selinux@tycho.nsa.gov,
	linux-security-module@vger.kernel.org, dhowells@redhat.com
Subject: [PATCH 01/37] KEYS: Increase the payload size when instantiating a key [ver #34]
Date: Fri, 29 Feb 2008 00:43:38 +0000	[thread overview]
Message-ID: <20080229004338.4142.73865.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <20080229004332.4142.51771.stgit@warthog.procyon.org.uk>

Increase the size of a payload that can be used to instantiate a key in
add_key() and keyctl_instantiate_key().  This permits huge CIFS SPNEGO blobs to
be passed around.  The limit is raised to 1MB.  If kmalloc() can't allocate a
buffer of sufficient size, vmalloc() will be tried instead.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 security/keys/keyctl.c |   38 ++++++++++++++++++++++++++++++--------
 1 files changed, 30 insertions(+), 8 deletions(-)


diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index d9ca15c..8ec8432 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -19,6 +19,7 @@
 #include <linux/capability.h>
 #include <linux/string.h>
 #include <linux/err.h>
+#include <linux/vmalloc.h>
 #include <asm/uaccess.h>
 #include "internal.h"
 
@@ -62,9 +63,10 @@ asmlinkage long sys_add_key(const char __user *_type,
 	char type[32], *description;
 	void *payload;
 	long ret;
+	bool vm;
 
 	ret = -EINVAL;
-	if (plen > 32767)
+	if (plen > 1024 * 1024 - 1)
 		goto error;
 
 	/* draw all the data into kernel space */
@@ -81,11 +83,18 @@ asmlinkage long sys_add_key(const char __user *_type,
 	/* pull the payload in if one was supplied */
 	payload = NULL;
 
+	vm = false;
 	if (_payload) {
 		ret = -ENOMEM;
 		payload = kmalloc(plen, GFP_KERNEL);
-		if (!payload)
-			goto error2;
+		if (!payload) {
+			if (plen <= PAGE_SIZE)
+				goto error2;
+			vm = true;
+			payload = vmalloc(plen);
+			if (!payload)
+				goto error2;
+		}
 
 		ret = -EFAULT;
 		if (copy_from_user(payload, _payload, plen) != 0)
@@ -113,7 +122,10 @@ asmlinkage long sys_add_key(const char __user *_type,
 
 	key_ref_put(keyring_ref);
  error3:
-	kfree(payload);
+	if (!vm)
+		kfree(payload);
+	else
+		vfree(payload);
  error2:
 	kfree(description);
  error:
@@ -821,9 +833,10 @@ long keyctl_instantiate_key(key_serial_t id,
 	key_ref_t keyring_ref;
 	void *payload;
 	long ret;
+	bool vm = false;
 
 	ret = -EINVAL;
-	if (plen > 32767)
+	if (plen > 1024 * 1024 - 1)
 		goto error;
 
 	/* the appropriate instantiation authorisation key must have been
@@ -843,8 +856,14 @@ long keyctl_instantiate_key(key_serial_t id,
 	if (_payload) {
 		ret = -ENOMEM;
 		payload = kmalloc(plen, GFP_KERNEL);
-		if (!payload)
-			goto error;
+		if (!payload) {
+			if (plen <= PAGE_SIZE)
+				goto error;
+			vm = true;
+			payload = vmalloc(plen);
+			if (!payload)
+				goto error;
+		}
 
 		ret = -EFAULT;
 		if (copy_from_user(payload, _payload, plen) != 0)
@@ -877,7 +896,10 @@ long keyctl_instantiate_key(key_serial_t id,
 	}
 
 error2:
-	kfree(payload);
+	if (!vm)
+		kfree(payload);
+	else
+		vfree(payload);
 error:
 	return ret;
 


  reply	other threads:[~2008-02-29  0:45 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-29  0:43 [PATCH 00/37] Permit filesystem local caching " David Howells
2008-02-29  0:43 ` David Howells [this message]
2008-02-29  0:43 ` [PATCH 02/37] KEYS: Check starting keyring as part of search " David Howells
2008-02-29  0:43 ` [PATCH 03/37] KEYS: Allow the callout data to be passed as a blob rather than a string " David Howells
2008-02-29  0:43 ` [PATCH 04/37] KEYS: Add keyctl function to get a security label " David Howells
2008-02-29  0:44 ` [PATCH 05/37] Security: Change current->fs[ug]id to current_fs[ug]id() " David Howells
2008-02-29  0:44 ` [PATCH 06/37] Security: Separate task security context from task_struct " David Howells
2008-02-29  0:44 ` [PATCH 07/37] Security: De-embed task security record from task and use refcounting " David Howells
2008-02-29  0:44 ` [PATCH 08/37] Security: Add a kernel_service object class to SELinux " David Howells
2008-02-29  0:44 ` [PATCH 09/37] Security: Allow kernel services to override LSM settings for task actions " David Howells
2008-02-29  0:44 ` [PATCH 10/37] Security: Make NFSD work with detached security " David Howells
2008-02-29  0:44 ` [PATCH 11/37] FS-Cache: Release page->private after failed readahead " David Howells
2008-02-29  0:44 ` [PATCH 12/37] FS-Cache: Recruit a couple of page flags for cache management " David Howells
2008-02-29  0:44 ` [PATCH 13/37] FS-Cache: Provide an add_wait_queue_tail() function " David Howells
2008-02-29  0:44 ` [PATCH 14/37] FS-Cache: Generic filesystem caching facility " David Howells
2008-02-29  0:44 ` [PATCH 15/37] CacheFiles: Add missing copy_page export for ia64 " David Howells
2008-02-29  0:44 ` [PATCH 16/37] CacheFiles: Be consistent about the use of mapping vs file->f_mapping in Ext3 " David Howells
2008-02-29  0:45 ` [PATCH 17/37] CacheFiles: Add a hook to write a single page of data to an inode " David Howells
2008-02-29  0:45 ` [PATCH 18/37] CacheFiles: Permit the page lock state to be monitored " David Howells
2008-02-29  0:45 ` [PATCH 19/37] CacheFiles: Export things for CacheFiles " David Howells
2008-02-29  0:45 ` [PATCH 20/37] CacheFiles: A cache that backs onto a mounted filesystem " David Howells
2008-02-29  0:45 ` [PATCH 21/37] NFS: Add comment banners to some NFS functions " David Howells
2008-02-29  0:45 ` [PATCH 22/37] NFS: Add FS-Cache option bit and debug bit " David Howells
2008-02-29  0:45 ` [PATCH 23/37] NFS: Permit local filesystem caching to be enabled for NFS " David Howells
2008-02-29  0:45 ` [PATCH 24/37] NFS: Register NFS for caching and retrieve the top-level index " David Howells
2008-02-29  0:45 ` [PATCH 25/37] NFS: Define and create server-level objects " David Howells
2008-02-29  0:45 ` [PATCH 26/37] NFS: Define and create superblock-level " David Howells
2008-02-29  0:45 ` [PATCH 27/37] NFS: Define and create inode-level cache " David Howells
2008-02-29  0:46 ` [PATCH 28/37] NFS: Use local disk inode cache " David Howells
2008-02-29  0:46 ` [PATCH 29/37] NFS: Invalidate FsCache page flags when cache removed " David Howells
2008-02-29  0:46 ` [PATCH 30/37] NFS: Add some new I/O event counters for FS-Cache events " David Howells
2008-02-29  0:46 ` [PATCH 31/37] NFS: FS-Cache page management " David Howells
2008-02-29  0:46 ` [PATCH 32/37] NFS: Add read context retention for FS-Cache to call back with " David Howells
2008-02-29  0:46 ` [PATCH 33/37] NFS: nfs_readpage_async() needs to be accessible as a fallback for local caching " David Howells
2008-02-29  0:46 ` [PATCH 34/37] NFS: Read pages from FS-Cache into an NFS inode " David Howells
2008-02-29  0:46 ` [PATCH 35/37] NFS: Store pages from an NFS inode into a local cache " David Howells
2008-02-29  0:46 ` [PATCH 36/37] NFS: Display local caching state " David Howells
2008-02-29  0:46 ` [PATCH 37/37] NFS: Add mount options to enable local caching on NFS " David Howells
2008-03-19 17:12 ` Performance degradation measurement [was Re: [PATCH 06/37] Security: Separate task security context from task_struct [ver #34]] David Howells
2008-03-23  5:17   ` Valdis.Kletnieks
2008-03-23 12:40   ` David Howells

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