SELinux: check open perms in dentry_open not inode_permission
Some operations, like searching a directory path or connecting a unix domain
socket, make explicit calls into inode_permission. Our choices are to
either try to come up with a signature for all of the explicit calls to
inode_permission and do not check open on those, or to move the open checks to
dentry_open where we know this is always an open operation. This patch moves
the checks to dentry_open.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c679ba6..03ff7db 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1686,35 +1686,6 @@
return av;
}
-/*
- * Convert a file mask to an access vector and include the correct open
- * open permission.
- */
-static inline u32 open_file_mask_to_av(int mode, int mask)
-{
- u32 av = file_mask_to_av(mode, mask);
-
- if (selinux_policycap_openperm) {
- /*
- * lnk files and socks do not really have an 'open'
- */
- if (S_ISREG(mode))
- av |= FILE__OPEN;
- else if (S_ISCHR(mode))
- av |= CHR_FILE__OPEN;
- else if (S_ISBLK(mode))
- av |= BLK_FILE__OPEN;
- else if (S_ISFIFO(mode))
- av |= FIFO_FILE__OPEN;
- else if (S_ISDIR(mode))
- av |= DIR__OPEN;
- else
- printk(KERN_ERR "SELinux: WARNING: inside %s with "
- "unknown mode:%x\n", __func__, mode);
- }
- return av;
-}
-
/* Convert a Linux file to an access vector. */
static inline u32 file_to_av(struct file *file)
{
@@ -1738,6 +1709,36 @@
return av;
}
+/*
+ * Convert a file to an access vector and include the correct open
+ * open permission.
+ */
+static inline u32 open_file_to_av(struct file *file)
+{
+ u32 av = file_to_av(file);
+
+ if (selinux_policycap_openperm) {
+ mode_t mode = file->f_path.dentry->d_inode->i_mode;
+ /*
+ * lnk files and socks do not really have an 'open'
+ */
+ if (S_ISREG(mode))
+ av |= FILE__OPEN;
+ else if (S_ISCHR(mode))
+ av |= CHR_FILE__OPEN;
+ else if (S_ISBLK(mode))
+ av |= BLK_FILE__OPEN;
+ else if (S_ISFIFO(mode))
+ av |= FIFO_FILE__OPEN;
+ else if (S_ISDIR(mode))
+ av |= DIR__OPEN;
+ else
+ printk(KERN_ERR "SELinux: WARNING: inside %s with "
+ "unknown mode:%o\n", __func__, mode);
+ }
+ return av;
+}
+
/* Hook functions begin here. */
static int selinux_ptrace_may_access(struct task_struct *child,
@@ -2654,7 +2655,7 @@
}
return inode_has_perm(current, inode,
- open_file_mask_to_av(inode->i_mode, mask), NULL);
+ file_mask_to_av(inode->i_mode, mask), NULL);
}
static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
@@ -3170,7 +3171,7 @@
* new inode label or new policy.
* This check is not redundant - do not remove.
*/
- return inode_has_perm(current, inode, file_to_av(file), NULL);
+ return inode_has_perm(current, inode, open_file_to_av(file), NULL);
}
/* task security operations */