[PATCH v2 1/6] xattr: Complete constify ->name member of "struct xattr"

[PATCH v2 1/6] xattr: Complete constify ->name member of "struct xattr"

[Roberto Sassu]

This patch completes commit 9548906b2bb7 ('xattr: Constify ->name member of
"struct xattr"'). It fixes the documentation of the inode_init_security
hook, by removing the xattr name from the objects that are expected to be
allocated by LSMs (only the value is allocated).

Also, it removes the kfree() of name and setting it to NULL in
reiserfs_security_free().

Fixes: 9548906b2bb7 ('xattr: Constify ->name member of "struct xattr"')
Cc: stable@vger.kernel.org
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 fs/reiserfs/xattr_security.c | 2 --
 include/linux/lsm_hooks.h    | 4 ++--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
index 8965c8e5e172..bb2a0062e0e5 100644
--- a/fs/reiserfs/xattr_security.c
+++ b/fs/reiserfs/xattr_security.c
@@ -95,9 +95,7 @@ int reiserfs_security_write(struct reiserfs_transaction_handle *th,
 
 void reiserfs_security_free(struct reiserfs_security_handle *sec)
 {
-	kfree(sec->name);
 	kfree(sec->value);
-	sec->name = NULL;
 	sec->value = NULL;
 }
 
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index fb7f3193753d..c5498f5174ce 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -219,8 +219,8 @@
  *	This hook is called by the fs code as part of the inode creation
  *	transaction and provides for atomic labeling of the inode, unlike
  *	the post_create/mkdir/... hooks called by the VFS.  The hook function
- *	is expected to allocate the name and value via kmalloc, with the caller
- *	being responsible for calling kfree after using them.
+ *	is expected to allocate the value via kmalloc, with the caller
+ *	being responsible for calling kfree after using it.
  *	If the security module does not use security attributes or does
  *	not wish to put a security attribute on this particular inode,
  *	then it should return -EOPNOTSUPP to skip this processing.
-- 
2.25.1

[PATCH v2 2/6] reiserfs: Add missing calls to reiserfs_security_free()

[Roberto Sassu]

Commit 57fe60df6241 ("reiserfs: add atomic addition of selinux attributes
during inode creation") defined reiserfs_security_free() to free the name
and value of a security xattr allocated by the active LSM through
security_old_inode_init_security(). However, this function is not called
in the reiserfs code.

Thus, this patch adds a call to reiserfs_security_free() whenever
reiserfs_security_init() is called, and initializes value to NULL, to avoid
to call kfree() on an uninitialized pointer.

Fixes: 57fe60df6241 ("reiserfs: add atomic addition of selinux attributes during inode creation")
Cc: stable@vger.kernel.org
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Mimi Zohar <zohar@linux.ibm.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 fs/reiserfs/namei.c          | 4 ++++
 fs/reiserfs/xattr_security.c | 1 +
 2 files changed, 5 insertions(+)

diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index e6eb05e2b2f1..6b5c51a77fae 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -695,6 +695,7 @@ static int reiserfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 
 out_failed:
 	reiserfs_write_unlock(dir->i_sb);
+	reiserfs_security_free(&security);
 	return retval;
 }
 
@@ -778,6 +779,7 @@ static int reiserfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 
 out_failed:
 	reiserfs_write_unlock(dir->i_sb);
+	reiserfs_security_free(&security);
 	return retval;
 }
 
@@ -877,6 +879,7 @@ static int reiserfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 	retval = journal_end(&th);
 out_failed:
 	reiserfs_write_unlock(dir->i_sb);
+	reiserfs_security_free(&security);
 	return retval;
 }
 
@@ -1193,6 +1196,7 @@ static int reiserfs_symlink(struct user_namespace *mnt_userns,
 	retval = journal_end(&th);
 out_failed:
 	reiserfs_write_unlock(parent_dir->i_sb);
+	reiserfs_security_free(&security);
 	return retval;
 }
 
diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
index bb2a0062e0e5..b1ad93b60475 100644
--- a/fs/reiserfs/xattr_security.c
+++ b/fs/reiserfs/xattr_security.c
@@ -50,6 +50,7 @@ int reiserfs_security_init(struct inode *dir, struct inode *inode,
 	int error;
 
 	sec->name = NULL;
+	sec->value = NULL;
 
 	/* Don't add selinux attributes on xattrs - they'll never get used */
 	if (IS_PRIVATE(dir))
-- 
2.25.1