From: Stephen Smalley Date: Wed, 14 Feb 2007 08:34:16 +0000 (-0800) Subject: [PATCH] selinux: enhance selinux to always ignore private inodes X-Git-Tag: v2.6.21-rc1~186 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bbaca6c2e7ef0f663bc31be4dad7cf530f6c4962;p=linux-2.6 [PATCH] selinux: enhance selinux to always ignore private inodes Hmmm...turns out to not be quite enough, as the /proc/sys inodes aren't truly private to the fs, so we can run into them in a variety of security hooks beyond just the inode hooks, such as security_file_permission (when reading and writing them via the vfs helpers), security_sb_mount (when mounting other filesystems on directories in proc like binfmt_misc), and deeper within the security module itself (as in flush_unauthorized_files upon inheritance across execve). So I think we have to add an IS_PRIVATE() guard within SELinux, as below. Note however that the use of the private flag here could be confusing, as these inodes are _not_ private to the fs, are exposed to userspace, and security modules must implement the sysctl hook to get any access control over them. Signed-off-by: Eric W. Biederman Signed-off-by: Stephen Smalley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b8ede1c760..b1ac22d231 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1077,6 +1077,9 @@ static int inode_has_perm(struct task_struct *tsk, struct inode_security_struct *isec; struct avc_audit_data ad; + if (unlikely (IS_PRIVATE (inode))) + return 0; + tsec = tsk->security; isec = inode->i_security;