selinux: don't revalidate an inode's label when explicitly setting it

There is no point in attempting to revalidate an inode's security
label when we are in the process of setting it.

Reported-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Paul Moore 2016-04-19 16:36:28 -04:00
parent 0fd71a620b
commit 2c97165bef

View File

@ -297,6 +297,13 @@ static struct inode_security_struct *inode_security(struct inode *inode)
return inode->i_security;
}
static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
{
struct inode *inode = d_backing_inode(dentry);
return inode->i_security;
}
/*
* Get the security label of a dentry's backing inode.
*/
@ -686,7 +693,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
struct superblock_security_struct *sbsec = sb->s_security;
const char *name = sb->s_type->name;
struct dentry *root = sbsec->sb->s_root;
struct inode_security_struct *root_isec = backing_inode_security(root);
struct inode_security_struct *root_isec;
u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
u32 defcontext_sid = 0;
char **mount_options = opts->mnt_opts;
@ -729,6 +736,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
&& (num_opts == 0))
goto out;
root_isec = backing_inode_security_novalidate(root);
/*
* parse the mount options, check if they are valid sids.
* also check if someone is trying to mount the same sb more
@ -3222,7 +3231,7 @@ static int selinux_inode_getsecurity(struct inode *inode, const char *name, void
static int selinux_inode_setsecurity(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
struct inode_security_struct *isec = inode_security(inode);
struct inode_security_struct *isec = inode_security_novalidate(inode);
u32 newsid;
int rc;