Re: [PATCH] Smack: fix smack_new_inode bogosities

From: Casey Schaufler
Date: Sun May 27 2012 - 17:33:02 EST


On 5/23/2012 5:46 PM, Casey Schaufler wrote:
> From: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
> Subject: [PATCH] Smack: fix smack_new_inode bogosities
>
> In January of 2012 Al Viro pointed out three bits of code that
> he titled "new_inode_smack bogosities". This patch repairs these
> errors.
>
> 1. smack_sb_kern_mount() included a NULL check that is impossible.
> The check and NULL case are removed.
> 2. smack_kb_kern_mount() included pointless locking. The locking is
> removed. Since this is the only place that lock was used the lock
> is removed from the superblock_smack structure.
> 3. smk_fill_super() incorrectly and unnecessarily set the Smack label
> for the smackfs root inode. The assignment has been removed.
>
> Targeted for git://gitorious.org/smack-next/kernel.git
>
> Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>


Applied to git://gitorious.org/smack-next/kernel.git

>
> ---
>
> security/smack/smack.h | 1 -
> security/smack/smack_lsm.c | 8 ++------
> security/smack/smackfs.c | 1 -
> 3 files changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index cc361b8..76feb31 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -43,7 +43,6 @@ struct superblock_smack {
> char *smk_hat;
> char *smk_default;
> int smk_initialized;
> - spinlock_t smk_sblock; /* for initialization */
> };
>
> struct socket_smack {
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index d583c05..5a4d52c 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -251,7 +251,6 @@ static int smack_sb_alloc_security(struct super_block *sb)
> sbsp->smk_floor = smack_known_floor.smk_known;
> sbsp->smk_hat = smack_known_hat.smk_known;
> sbsp->smk_initialized = 0;
> - spin_lock_init(&sbsp->smk_sblock);
>
> sb->s_security = sbsp;
>
> @@ -332,13 +331,10 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
> char *commap;
> char *nsp;
>
> - spin_lock(&sp->smk_sblock);
> - if (sp->smk_initialized != 0) {
> - spin_unlock(&sp->smk_sblock);
> + if (sp->smk_initialized != 0)
> return 0;
> - }
> +
> sp->smk_initialized = 1;
> - spin_unlock(&sp->smk_sblock);
>
> for (op = data; op != NULL; op = commap) {
> commap = strchr(op, ',');
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index 1810c9a..3686db7 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -2051,7 +2051,6 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
> }
>
> root_inode = sb->s_root->d_inode;
> - root_inode->i_security = new_inode_smack(smack_known_floor.smk_known);
>
> return 0;
> }
>
>
>
>

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