Re: [PATCH v4 1/5] reiserfs: Add missing calls to reiserfs_security_free()

From: Paul Moore
Date: Mon Nov 21 2022 - 18:43:00 EST


On Thu, Nov 10, 2022 at 4:47 AM Roberto Sassu
<roberto.sassu@xxxxxxxxxxxxxxx> wrote:
>
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
>
> 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, add a call to reiserfs_security_free() whenever
> reiserfs_security_init() is called, and initialize value to NULL, to avoid
> to call kfree() on an uninitialized pointer.
>
> Finally, remove the kfree() for the xattr name, as it is not allocated
> anymore.
>
> Fixes: 57fe60df6241 ("reiserfs: add atomic addition of selinux attributes during inode creation")
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Jeff Mahoney <jeffm@xxxxxxxx>
> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Reported-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> ---
> fs/reiserfs/namei.c | 4 ++++
> fs/reiserfs/xattr_security.c | 2 +-
> 2 files changed, 5 insertions(+), 1 deletion(-)

If I'm understanding this patch correctly, this is a standalone
bugfix, right? Any reason this shouldn't be merged now, independent
of the rest of patches in this patchset?

> diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
> index 3d7a35d6a18b..b916859992ec 100644
> --- a/fs/reiserfs/namei.c
> +++ b/fs/reiserfs/namei.c
> @@ -696,6 +696,7 @@ 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;
> }
>
> @@ -779,6 +780,7 @@ 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;
> }
>
> @@ -878,6 +880,7 @@ 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;
> }
>
> @@ -1194,6 +1197,7 @@ 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 8965c8e5e172..857a65b05726 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))
> @@ -95,7 +96,6 @@ 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;
> --
> 2.25.1
>


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