From: Fan Wu <wufan@linux.microsoft.com>
To: corbet@lwn.net, zohar@linux.ibm.com, jmorris@namei.org,
serge@hallyn.com, tytso@mit.edu, ebiggers@kernel.org,
axboe@kernel.dk, agk@redhat.com, snitzer@kernel.org,
eparis@redhat.com, paul@paul-moore.com
Cc: linux-doc@vger.kernel.org, linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-fscrypt@vger.kernel.org, linux-block@vger.kernel.org,
dm-devel@lists.linux.dev, audit@vger.kernel.org,
linux-kernel@vger.kernel.org, Fan Wu <wufan@linux.microsoft.com>
Subject: [RFC PATCH v13 07/20] security: add new securityfs delete function
Date: Wed, 28 Feb 2024 16:54:49 -0800 [thread overview]
Message-ID: <1709168102-7677-8-git-send-email-wufan@linux.microsoft.com> (raw)
In-Reply-To: <1709168102-7677-1-git-send-email-wufan@linux.microsoft.com>
When deleting a directory in the security file system, the existing
securityfs_remove requires the directory to be empty, otherwise
it will do nothing. This leads to a potential risk that the security
file system might be in an unclean state when the intended deletion
did not happen.
This commit introduces a new function securityfs_recursive_remove
to recursively delete a directory without leaving an unclean state.
Co-developed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
---
v1-v8:
+ Not present
v9:
+ Introduced
v10:
+ No changes
v11:
+ Fix code style issues
v12:
+ No changes
v13:
+ No changes
---
include/linux/security.h | 1 +
security/inode.c | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/include/linux/security.h b/include/linux/security.h
index 619e17e59532..e74e8b2a07f4 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -2029,6 +2029,7 @@ struct dentry *securityfs_create_symlink(const char *name,
const char *target,
const struct inode_operations *iops);
extern void securityfs_remove(struct dentry *dentry);
+extern void securityfs_recursive_remove(struct dentry *dentry);
#else /* CONFIG_SECURITYFS */
diff --git a/security/inode.c b/security/inode.c
index 9e7cde913667..f21847badb7d 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -313,6 +313,31 @@ void securityfs_remove(struct dentry *dentry)
}
EXPORT_SYMBOL_GPL(securityfs_remove);
+static void remove_one(struct dentry *victim)
+{
+ simple_release_fs(&mount, &mount_count);
+}
+
+/**
+ * securityfs_recursive_remove - recursively removes a file or directory
+ *
+ * @dentry: a pointer to a the dentry of the file or directory to be removed.
+ *
+ * This function recursively removes a file or directory in securityfs that was
+ * previously created with a call to another securityfs function (like
+ * securityfs_create_file() or variants thereof.)
+ */
+void securityfs_recursive_remove(struct dentry *dentry)
+{
+ if (IS_ERR_OR_NULL(dentry))
+ return;
+
+ simple_pin_fs(&fs_type, &mount, &mount_count);
+ simple_recursive_removal(dentry, remove_one);
+ simple_release_fs(&mount, &mount_count);
+}
+EXPORT_SYMBOL_GPL(securityfs_recursive_remove);
+
#ifdef CONFIG_SECURITY
static struct dentry *lsm_dentry;
static ssize_t lsm_read(struct file *filp, char __user *buf, size_t count,
--
2.43.1
next prev parent reply other threads:[~2024-02-29 0:55 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-29 0:54 [RFC PATCH v13 00/20] Integrity Policy Enforcement LSM (IPE) Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 01/20] security: add ipe lsm Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 02/20] ipe: add policy parser Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 03/20] ipe: add evaluation loop Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 04/20] ipe: add LSM hooks on execution and kernel read Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 05/20] initramfs|security: Add a security hook to do_populate_rootfs() Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 06/20] ipe: introduce 'boot_verified' as a trust provider Fan Wu
2024-02-29 0:54 ` Fan Wu [this message]
2024-02-29 0:54 ` [RFC PATCH v13 08/20] ipe: add userspace interface Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 09/20] uapi|audit|ipe: add ipe auditing support Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 10/20] ipe: add permissive toggle Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 11/20] block|security: add LSM blob to block_device Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 12/20] dm verity: set DM_TARGET_SINGLETON feature flag Fan Wu
2024-03-02 16:01 ` Mike Snitzer
2024-02-29 0:54 ` [RFC PATCH v13 13/20] dm: add finalize hook to target_type Fan Wu
2024-03-02 16:13 ` Mike Snitzer
2024-02-29 0:54 ` [RFC PATCH v13 14/20] dm verity: consume root hash digest and signature data via LSM hook Fan Wu
2024-03-02 16:22 ` Mike Snitzer
2024-03-02 16:37 ` Mike Snitzer
2024-02-29 0:54 ` [RFC PATCH v13 15/20] ipe: add support for dm-verity as a trust provider Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 16/20] fsverity: consume builtin signature via LSM hook Fan Wu
2024-02-29 0:54 ` [RFC PATCH v13 17/20] ipe: enable support for fs-verity as a trust provider Fan Wu
2024-02-29 4:01 ` Randy Dunlap
2024-02-29 4:46 ` Eric Biggers
2024-02-29 18:59 ` Fan Wu
2024-02-29 19:42 ` Eric Biggers
2024-02-29 19:59 ` Fan Wu
2024-02-29 0:55 ` [RFC PATCH v13 18/20] scripts: add boot policy generation program Fan Wu
2024-02-29 0:55 ` [RFC PATCH v13 19/20] ipe: kunit test for parser Fan Wu
2024-02-29 0:55 ` [RFC PATCH v13 20/20] documentation: add ipe documentation Fan Wu
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