commit db978da8fa1d0819b210c137d31a339149b88875
author Andreas Gruenbacher <agruenba@redhat.com> Thu Nov 10 22:18:28 2016 +0100
committer Paul Moore <paul@paul-moore.com> Mon Nov 14 15:39:48 2016 -0500
tree 877976508c0ebadc5372fecdb82f0e91121c1c1a
parent 420591128cb206201dc444c2d42fb6f299b2ecd0

proc: Pass file mode to proc_pid_make_inode

Pass the file mode of the proc inode to be created to
proc_pid_make_inode.  In proc_pid_make_inode, initialize inode->i_mode
before calling security_task_to_inode.  This allows selinux to set
isec->sclass right away without introducing "half-initialized" inode
security structs.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

fs/proc/base.c

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 8e65446..9de05e5 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1663,7 +1663,8 @@ const struct inode_operations proc_pid_link_inode_operations = {
 
 /* building an inode */
 
-struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
+struct inode *proc_pid_make_inode(struct super_block * sb,
+				  struct task_struct *task, umode_t mode)
 {
 	struct inode * inode;
 	struct proc_inode *ei;
@@ -1677,6 +1678,7 @@ struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *t
 
 	/* Common stuff */
 	ei = PROC_I(inode);
+	inode->i_mode = mode;
 	inode->i_ino = get_next_ino();
 	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 	inode->i_op = &proc_def_inode_operations;
@@ -2003,7 +2005,9 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
 	struct proc_inode *ei;
 	struct inode *inode;
 
-	inode = proc_pid_make_inode(dir->i_sb, task);
+	inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK |
+				    ((mode & FMODE_READ ) ? S_IRUSR : 0) |
+				    ((mode & FMODE_WRITE) ? S_IWUSR : 0));
 	if (!inode)
 		return -ENOENT;
 
@@ -2012,12 +2016,6 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
 
 	inode->i_op = &proc_map_files_link_inode_operations;
 	inode->i_size = 64;
-	inode->i_mode = S_IFLNK;
-
-	if (mode & FMODE_READ)
-		inode->i_mode |= S_IRUSR;
-	if (mode & FMODE_WRITE)
-		inode->i_mode |= S_IWUSR;
 
 	d_set_d_op(dentry, &tid_map_files_dentry_operations);
 	d_add(dentry, inode);
@@ -2371,12 +2369,11 @@ static int proc_pident_instantiate(struct inode *dir,
 	struct inode *inode;
 	struct proc_inode *ei;
 
-	inode = proc_pid_make_inode(dir->i_sb, task);
+	inode = proc_pid_make_inode(dir->i_sb, task, p->mode);
 	if (!inode)
 		goto out;
 
 	ei = PROC_I(inode);
-	inode->i_mode = p->mode;
 	if (S_ISDIR(inode->i_mode))
 		set_nlink(inode, 2);	/* Use getattr to fix if necessary */
 	if (p->iop)
@@ -3058,11 +3055,10 @@ static int proc_pid_instantiate(struct inode *dir,
 {
 	struct inode *inode;
 
-	inode = proc_pid_make_inode(dir->i_sb, task);
+	inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
 	if (!inode)
 		goto out;
 
-	inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
 	inode->i_op = &proc_tgid_base_inode_operations;
 	inode->i_fop = &proc_tgid_base_operations;
 	inode->i_flags|=S_IMMUTABLE;
@@ -3351,11 +3347,10 @@ static int proc_task_instantiate(struct inode *dir,
 	struct dentry *dentry, struct task_struct *task, const void *ptr)
 {
 	struct inode *inode;
-	inode = proc_pid_make_inode(dir->i_sb, task);
+	inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
 
 	if (!inode)
 		goto out;
-	inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
 	inode->i_op = &proc_tid_base_inode_operations;
 	inode->i_fop = &proc_tid_base_operations;
 	inode->i_flags|=S_IMMUTABLE;