Eric Paris wrote:
> SELinux needs to pass the MAY_ACCESS flag so it can handle auditting
> correctly.
I'm not sure that I like the direction this is heading. Excesses
of granularity don't come about from a single change like this,
but from their repeated application and tendency to inspire others
to see breaking out special cases as an easy quick fix.
> Presently the masking of MAY_* flags is done in the VFS. In
> order to allow LSMs to decide what flags they care about and what flags
> they don't just pass them all and the each LSM mask off what they don't
> need. This patch should contain no functional changes to either the VFS or
> any LSM.
>
> Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
>
I'm acking this not because I like the approach but because I don't
see it as causing any damage and I don't have a better solution to
the audit problem that wouldn't require a redesign of SELinux.
Acked-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
> ---
>
> fs/namei.c | 3 +--
> security/selinux/hooks.c | 2 ++
> security/smack/smack_lsm.c | 2 ++
> 3 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/fs/namei.c b/fs/namei.c
> index f068192..3b0f583 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -282,8 +282,7 @@ int inode_permission(struct inode *inode, int mask)
> if (retval)
> return retval;
>
> - return security_inode_permission(inode,
> - mask & (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND));
> + return security_inode_permission(inode, mask);
> }
>
> /**
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 740a71f..344ba62 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -2700,6 +2700,8 @@ static int selinux_inode_permission(struct inode *inode, int mask)
> {
> const struct cred *cred = current_cred();
>
> + mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
> +
> if (!mask) {
> /* No permission to check. Existence test. */
> return 0;
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index f1b6846..df467f4 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -599,6 +599,8 @@ static int smack_inode_rename(struct inode *old_inode,
> static int smack_inode_permission(struct inode *inode, int mask)
> {
> struct smk_audit_info ad;
> +
> + mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
> /*
> * No permission to check. Existence test. Yup, it's there.
> */
>
>
>
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