security: make LSMs explicitly mask off permissions (d09ca739) · Commits · 戴 / test

SELinux needs to pass the MAY_ACCESS flag so it can handle auditting correctly. 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@redhat.com> Acked-by:

Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by:

James Morris <jmorris@namei.org>

fs/namei.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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);
		}

		/**

security/selinux/hooks.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -2645,6 +2645,8 @@ 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;

security/smack/smack_lsm.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -598,6 +598,8 @@ 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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