[PATCH 5.19 0054/1157] fs: Add missing umask strip in vfs_tmpfile

Greg Kroah-Hartman
2022-08-15T22:08:07Z

From: Yang Xu <xuyang2018.jy@fujitsu.com>

commit ac6800e279a22b28f4fc21439843025a0d5bf03e upstream.

All creation paths except for O_TMPFILE handle umask in the vfs directly
if the filesystem doesn't support or enable POSIX ACLs. If the filesystem
does then umask handling is deferred until posix_acl_create().
Because, O_TMPFILE misses umask handling in the vfs it will not honor
umask settings. Fix this by adding the missing umask handling.

Link: https://lore.kernel.org/r/1657779088-2242-2-git-send-email-xuyang2018.jy@fujitsu.com
Fixes: 60545d0d4610 ("[O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now...")
Cc: <stable@vger.kernel.org> # 4.19+
Reported-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-and-Tested-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/namei.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3565,6 +3565,8 @@ struct dentry *vfs_tmpfile(struct user_n
child = d_alloc(dentry, &slash_name);
if (unlikely(!child))
goto out_err;
+ if (!IS_POSIXACL(dir))
+ mode &= ~current_umask();
error = dir->i_op->tmpfile(mnt_userns, dir, child, mode);
if (error)
goto out_err;