Commit c2c44ec2 authored Jul 27, 2019 by Al Viro

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>

parent 19a1c409

fs/super.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -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);
		}

		/**

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