From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D381F19DF4C; Wed, 23 Apr 2025 14:55:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745420136; cv=none; b=MyOfBsrxyN3ZStxB7vp1xpZBqGnSg8/aOzv9dzzQC1zGSfXZKnIKdvYhzNafVRAP4SYcRYMHs6gWpnkpp9sni+r3dbpenoqkSNft/TpKkG6beaez+7UerRy3vzubDlbNo9Sy78RKxolNK5jdDgC2htpkAH0q7lrZmydpi3xN6e4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745420136; c=relaxed/simple; bh=dAHsnDrgZiIHGc6P+sJCk9p+7LN3otYIc29KptDq5G4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lq+6RgQjeABkH5Z22eV0vXlJohX3K/aC61EiKD+2vj4oFJG7xFsyeT9Ao82HSdRN1S5sGXzq1bMP/xjAu14Kr+RbNzVX9CBjwpiMJ94HPhEIsaowtkVMU+gOeklp9Zx6DXK+h04pn1qfYK9cy94Seqg8U+IfbL13nFjRr1dz02A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IX61t83e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="IX61t83e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68802C4CEE2; Wed, 23 Apr 2025 14:55:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745420136; bh=dAHsnDrgZiIHGc6P+sJCk9p+7LN3otYIc29KptDq5G4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IX61t83ek6jycrdCwcygoI6jyNCR6mjwupw+IDW2IaSguqgkY/05SwUvvriRWmvM9 txefIAJloz4vnm1pD0I7O7g457MBjegz+19iZhOPc6g9y/HriT6xU42b8JPUeq63qN fF5OyHRu95lvTIKsJNnUa9OoXlieB7mEeLCKAYEg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Trond Myklebust , "Eric W. Biederman" , Christian Brauner , Sasha Levin Subject: [PATCH 6.1 020/291] umount: Allow superblock owners to force umount Date: Wed, 23 Apr 2025 16:40:09 +0200 Message-ID: <20250423142625.230055412@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250423142624.409452181@linuxfoundation.org> References: <20250423142624.409452181@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust [ Upstream commit e1ff7aa34dec7e650159fd7ca8ec6af7cc428d9f ] Loosen the permission check on forced umount to allow users holding CAP_SYS_ADMIN privileges in namespaces that are privileged with respect to the userns that originally mounted the filesystem. Signed-off-by: Trond Myklebust Link: https://lore.kernel.org/r/12f212d4ef983714d065a6bb372fbb378753bf4c.1742315194.git.trond.myklebust@hammerspace.com Acked-by: "Eric W. Biederman" Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/namespace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index 59a9f877738b2..57166cc7e5117 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1777,6 +1777,7 @@ static void warn_mandlock(void) static int can_umount(const struct path *path, int flags) { struct mount *mnt = real_mount(path->mnt); + struct super_block *sb = path->dentry->d_sb; if (!may_mount()) return -EPERM; @@ -1786,7 +1787,7 @@ static int can_umount(const struct path *path, int flags) return -EINVAL; if (mnt->mnt.mnt_flags & MNT_LOCKED) /* Check optimistically */ return -EINVAL; - if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN)) + if (flags & MNT_FORCE && !ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) return -EPERM; return 0; } -- 2.39.5