4 files changed, 39 insertions, 23 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 476f3ebf437e..238b7aa26f68 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -657,10 +657,10 @@ int setup_arg_pages(struct linux_binprm *bprm,
 	unsigned long rlim_stack;
 
 #ifdef CONFIG_STACK_GROWSUP
-	/* Limit stack size to 1GB */
+	/* Limit stack size */
 	stack_base = rlimit_max(RLIMIT_STACK);
-	if (stack_base > (1 << 30))
-		stack_base = 1 << 30;
+	if (stack_base > STACK_SIZE_MAX)
+		stack_base = STACK_SIZE_MAX;
 
 	/* Make sure we didn't let the argument array grow too large. */
 	if (vma->vm_end - vma->vm_start > stack_base)
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index e01ea4a14a01..5e9a80cfc3d8 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -610,6 +610,7 @@ static void kernfs_put_open_node(struct kernfs_node *kn,
 static int kernfs_fop_open(struct inode *inode, struct file *file)
 {
 	struct kernfs_node *kn = file->f_path.dentry->d_fsdata;
+	struct kernfs_root *root = kernfs_root(kn);
 	const struct kernfs_ops *ops;
 	struct kernfs_open_file *of;
 	bool has_read, has_write, has_mmap;
@@ -624,14 +625,16 @@ static int kernfs_fop_open(struct inode *inode, struct file *file)
 	has_write = ops->write || ops->mmap;
 	has_mmap = ops->mmap;
 
-	/* check perms and supported operations */
-	if ((file->f_mode & FMODE_WRITE) &&
-	    (!(inode->i_mode & S_IWUGO) || !has_write))
-		goto err_out;
+	/* see the flag definition for details */
+	if (root->flags & KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK) {
+		if ((file->f_mode & FMODE_WRITE) &&
+		    (!(inode->i_mode & S_IWUGO) || !has_write))
+			goto err_out;
 
-	if ((file->f_mode & FMODE_READ) &&
-	    (!(inode->i_mode & S_IRUGO) || !has_read))
-		goto err_out;
+		if ((file->f_mode & FMODE_READ) &&
+		    (!(inode->i_mode & S_IRUGO) || !has_read))
+			goto err_out;
+	}
 
 	/* allocate a kernfs_open_file for the file */
 	error = -ENOMEM;
diff --git a/fs/locks.c b/fs/locks.c
index e663aeac579e..e390bd9ae068 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -389,18 +389,6 @@ static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl,
 	fl->fl_ops = NULL;
 	fl->fl_lmops = NULL;
 
-	/* Ensure that fl->fl_filp has compatible f_mode */
-	switch (l->l_type) {
-	case F_RDLCK:
-		if (!(filp->f_mode & FMODE_READ))
-			return -EBADF;
-		break;
-	case F_WRLCK:
-		if (!(filp->f_mode & FMODE_WRITE))
-			return -EBADF;
-		break;
-	}
-
 	return assign_type(fl, l->l_type);
 }
 
@@ -2034,6 +2022,22 @@ static int do_lock_file_wait(struct file *filp, unsigned int cmd,
 	return error;
 }
 
+/* Ensure that fl->fl_filp has compatible f_mode for F_SETLK calls */
+static int
+check_fmode_for_setlk(struct file_lock *fl)
+{
+	switch (fl->fl_type) {
+	case F_RDLCK:
+		if (!(fl->fl_file->f_mode & FMODE_READ))
+			return -EBADF;
+		break;
+	case F_WRLCK:
+		if (!(fl->fl_file->f_mode & FMODE_WRITE))
+			return -EBADF;
+	}
+	return 0;
+}
+
 /* Apply the lock described by l to an open file descriptor.
  * This implements both the F_SETLK and F_SETLKW commands of fcntl().
  */
@@ -2071,6 +2075,10 @@ again:
 	if (error)
 		goto out;
 
+	error = check_fmode_for_setlk(file_lock);
+	if (error)
+		goto out;
+
 	/*
 	 * If the cmd is requesting file-private locks, then set the
 	 * FL_OFDLCK flag and override the owner.
@@ -2206,6 +2214,10 @@ again:
 	if (error)
 		goto out;
 
+	error = check_fmode_for_setlk(file_lock);
+	if (error)
+		goto out;
+
 	/*
 	 * If the cmd is requesting file-private locks, then set the
 	 * FL_OFDLCK flag and override the owner.
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index a66ad6196f59..8794423f7efb 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -63,7 +63,8 @@ int __init sysfs_init(void)
 {
 	int err;
 
-	sysfs_root = kernfs_create_root(NULL, 0, NULL);
+	sysfs_root = kernfs_create_root(NULL, KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
+					NULL);
 	if (IS_ERR(sysfs_root))
 		return PTR_ERR(sysfs_root);