CVE-2016-9685 (published 2016-12-28T07:59Z)

Multiple memory leaks in error paths in fs/xfs/xfs_attr_list.c in the Linux kernel before 4.5.1 allow local users to cause a denial of service (memory consumption) via crafted XFS filesystem operations.

Severity: MEDIUM
CVSS v2 base score: 4.9 (AV:L/AC:L/Au:N/C:N/I:N/A:C)
CVSS v3 base score: 5.5, MEDIUM (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)

Weakness information:
cwe_id: CWE-400
cwe_name: Uncontrolled Resource Consumption
description: The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
extended_description: 
            Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.
            There are at least three distinct scenarios which can commonly lead to resource exhaustion:
               
                  Lack of throttling for the number of allocated resources
                  Losing all references to a resource before reaching the shutdown stage
                  Not closing/returning a resource after processing
               
            Resource exhaustion problems are often result due to an incorrect implementation of the following situations:
               
                  Error conditions and other exceptional circumstances.
                  Confusion over which part of the program is responsible for releasing the resource.
               
         
         

Fix information:
repo_url: https://github.com/torvalds/linux
commit_details: repo_url: https://github.com/torvalds/linux
author: Mateusz Guzik
author_date: 2016-03-02 09:51:09+11:00
msg: xfs: fix two memory leaks in xfs_attr_list.c error paths

This plugs 2 trivial leaks in xfs_attr_shortform_list and
xfs_attr3_leaf_list_int.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
repository: repo_url: https://github.com/torvalds/linux
repo_name: torvalds/linux
description: Linux kernel source tree
repo_language: C
owner: torvalds
file_changes: filename: xfs_attr_list.c
change_type: ModificationType.MODIFY
diff: @@ -202,8 +202,10 @@ xfs_attr_shortform_list(xfs_attr_list_context_t *context)
 					sbp->namelen,
 					sbp->valuelen,
 					&sbp->name[sbp->namelen]);
-		if (error)
+		if (error) {
+			kmem_free(sbuf);
 			return error;
+		}
 		if (context->seen_enough)
 			break;
 		cursor->offset++;
@@ -454,14 +456,13 @@ xfs_attr3_leaf_list_int(
 				args.rmtblkcnt = xfs_attr3_rmt_blocks(
 							args.dp->i_mount, valuelen);
 				retval = xfs_attr_rmtval_get(&args);
-				if (retval)
-					return retval;
-				retval = context->put_listent(context,
-						entry->flags,
-						name_rmt->name,
-						(int)name_rmt->namelen,
-						valuelen,
-						args.value);
+				if (!retval)
+					retval = context->put_listent(context,
+							entry->flags,
+							name_rmt->name,
+							(int)name_rmt->namelen,
+							valuelen,
+							args.value);
 				kmem_free(args.value);
 			} else {
 				retval = context->put_listent(context,

programming_language: C