From: "Mickaël Salaün" <mic@digikod.net>
To: James Morris <jmorris@namei.org>, Jann Horn <jannh@google.com>,
"Serge E . Hallyn" <serge@hallyn.com>
Cc: "Mickaël Salaün" <mic@digikod.net>,
"Shuah Khan" <shuah@kernel.org>,
"Vincent Dagonneau" <vincent.dagonneau@ssi.gouv.fr>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: [PATCH v1 1/9] landlock: Fix memory allocation error handling
Date: Wed, 11 Nov 2020 22:34:34 +0100 [thread overview]
Message-ID: <20201111213442.434639-2-mic@digikod.net> (raw)
In-Reply-To: <20201111213442.434639-1-mic@digikod.net>
Handle memory allocation errors in landlock_create_object() call. This
prevent to inadvertently hold an inode. Also, make get_inode_object()
more readable.
Cc: James Morris <jmorris@namei.org>
Cc: Jann Horn <jannh@google.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
---
security/landlock/fs.c | 5 +++++
security/landlock/object.c | 5 +++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index d8c5d19ac2af..b67c821bb40b 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -9,6 +9,7 @@
#include <linux/atomic.h>
#include <linux/compiler_types.h>
#include <linux/dcache.h>
+#include <linux/err.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -98,6 +99,8 @@ static struct landlock_object *get_inode_object(struct inode *const inode)
* holding any locks).
*/
new_object = landlock_create_object(&landlock_fs_underops, inode);
+ if (IS_ERR(new_object))
+ return new_object;
spin_lock(&inode->i_lock);
object = rcu_dereference_protected(inode_sec->object,
@@ -145,6 +148,8 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset,
access_rights |= _LANDLOCK_ACCESS_FS_MASK & ~ruleset->fs_access_mask;
rule.access = access_rights;
rule.object = get_inode_object(d_backing_inode(path->dentry));
+ if (IS_ERR(rule.object))
+ return PTR_ERR(rule.object);
mutex_lock(&ruleset->lock);
err = landlock_insert_rule(ruleset, &rule, false);
mutex_unlock(&ruleset->lock);
diff --git a/security/landlock/object.c b/security/landlock/object.c
index a71644ee72a7..54ba0327002a 100644
--- a/security/landlock/object.c
+++ b/security/landlock/object.c
@@ -8,6 +8,7 @@
#include <linux/bug.h>
#include <linux/compiler_types.h>
+#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/rcupdate.h>
#include <linux/refcount.h>
@@ -23,10 +24,10 @@ struct landlock_object *landlock_create_object(
struct landlock_object *new_object;
if (WARN_ON_ONCE(!underops || !underobj))
- return NULL;
+ return ERR_PTR(-ENOENT);
new_object = kzalloc(sizeof(*new_object), GFP_KERNEL_ACCOUNT);
if (!new_object)
- return NULL;
+ return ERR_PTR(-ENOMEM);
refcount_set(&new_object->usage, 1);
spin_lock_init(&new_object->lock);
new_object->underops = underops;
--
2.29.2
next prev parent reply other threads:[~2020-11-11 21:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-11 21:34 [PATCH v1 0/9] Landlock fixes Mickaël Salaün
2020-11-11 21:34 ` Mickaël Salaün [this message]
2020-11-11 21:34 ` [PATCH v1 2/9] landlock: Cosmetic fixes for filesystem management Mickaël Salaün
2020-11-20 1:37 ` James Morris
2020-11-11 21:34 ` [PATCH v1 3/9] landlock: Enforce deterministic interleaved path rules Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 4/9] landlock: Always intersect access rights Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 5/9] landlock: Add extra checks when inserting a rule Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 6/9] selftests/landlock: Extend layout1.inherit_superset Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 7/9] landlock: Clean up get_ruleset_from_fd() Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 8/9] landlock: Add help to enable Landlock as a stacked LSM Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 9/9] landlock: Extend documentation about limitations Mickaël Salaün
2020-11-12 4:59 ` [PATCH v1 0/9] Landlock fixes James Morris
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