pass creds to get_empty_filp(), make sure dentry_open() passes the right creds

... and rename get_empty_filp() to alloc_empty_file().

dentry_open() gets creds as argument, but the only thing that sees those is
security_file_open() - file->f_cred still ends up with current_cred().  For
almost all callers it's the same thing, but there are several broken cases.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/file_table.c b/fs/file_table.c
index 086c3f5..76cfa4c 100644 (file)
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -101,9 +101,8 @@ int proc_nr_files(struct ctl_table *table, int write,
  * done, you will imbalance int the mount's writer count
  * and a warning at __fput() time.
  */
-struct file *get_empty_filp(void)
+struct file *alloc_empty_file(const struct cred *cred)
 {
-       const struct cred *cred = current_cred();
        static long old_max;
        struct file *f;
        int error;
@@ -161,7 +160,7 @@ struct file *alloc_file(const struct path *path, int flags,
 {
        struct file *file;
 
-       file = get_empty_filp();
+       file = alloc_empty_file(current_cred());
        if (IS_ERR(file))
                return file;
 

diff --git a/fs/internal.h b/fs/internal.h
index 5645b4e..66473bf 100644 (file)
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -93,7 +93,7 @@ extern void chroot_fs_refs(const struct path *, const struct path *);
 /*
  * file_table.c
  */
-extern struct file *get_empty_filp(void);
+extern struct file *alloc_empty_file(const struct cred *);
 
 /*
  * super.c

diff --git a/fs/namei.c b/fs/namei.c
index 734cef5..af2ec18 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3513,7 +3513,7 @@ static struct file *path_openat(struct nameidata *nd,
        int opened = 0;
        int error;
 
-       file = get_empty_filp();
+       file = alloc_empty_file(current_cred());
        if (IS_ERR(file))
                return file;
 

diff --git a/fs/open.c b/fs/open.c
index 530da96..0061f9e 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -921,7 +921,7 @@ struct file *dentry_open(const struct path *path, int flags,
        /* We must always pass in a valid mount pointer. */
        BUG_ON(!path->mnt);
 
-       f = get_empty_filp();
+       f = alloc_empty_file(cred);
        if (!IS_ERR(f)) {
                f->f_flags = flags;
                error = vfs_open(path, f, cred);