From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 27 Jul 2019 12:29:57 +0000 (-0400)
Subject: Unbreak mount_capable()
X-Git-Tag: v5.15~5795^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c2c44ec20a8496f7a3b3401c092afe96908eced1;p=platform%2Fkernel%2Flinux-starfive.git

Unbreak mount_capable()

In "consolidate the capability checks in sget_{fc,userns}())" the
wrong argument had been passed to mount_capable() by sget_fc().
That mistake had been further obscured later, when switching
mount_capable() to fs_context has moved the calculation of
bogus argument from sget_fc() to mount_capable() itself.  It
should've been fc->user_ns all along.

Screwed-up-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Christian Brauner <christian@brauner.io>
Tested-by: Christian Brauner <christian@brauner.io>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/super.c b/fs/super.c
index 113c58f..5960578 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -478,13 +478,10 @@ EXPORT_SYMBOL(generic_shutdown_super);
 
 bool mount_capable(struct fs_context *fc)
 {
-	struct user_namespace *user_ns = fc->global ? &init_user_ns
-						    : fc->user_ns;
-
 	if (!(fc->fs_type->fs_flags & FS_USERNS_MOUNT))
 		return capable(CAP_SYS_ADMIN);
 	else
-		return ns_capable(user_ns, CAP_SYS_ADMIN);
+		return ns_capable(fc->user_ns, CAP_SYS_ADMIN);
 }
 
 /**