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 BFB2D2571AE; Thu, 17 Apr 2025 18:39:48 +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=1744915188; cv=none; b=TSsT77kgj1FOE6AjQeM5VTSgFLpmgilyqnecEnYgeZgRCyddK9R57/+LCIAUxIY517tEt4y23bs/KK4H+oVJJRQsSAoyC9w4DIucMHqxDQ2eY8y8Jn6N2qOp8xv/C7Do6iD2nfOZ8PDxGaX1l+YwWg0FgpMnNzgDbFp6F3XIiTc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744915188; c=relaxed/simple; bh=k2Frq0YEFHLhNsZldau92A3GQT+1yTk01jy1VQbDzBQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DxEvOm0Kiy9FHF4WTiiCPD0FH5HDNsAlk4LRRuZAtdPEwrlquCB/P8cMixe77lhb6VH2S3pI14c9FbP+5hXO9+Lg/6HQFvIg/X2Q3Isqfzmi01pDYdtJF0Eiaiq+NM2w3klZE6WRH1Rj94x5PsM4WjmDC7X8uemw0Ng1+cU+I8k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TrfoKJA1; 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="TrfoKJA1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48768C4CEE4; Thu, 17 Apr 2025 18:39:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744915188; bh=k2Frq0YEFHLhNsZldau92A3GQT+1yTk01jy1VQbDzBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TrfoKJA1RbveEYvw8Qk1ePzyYclbKDZtbsTjSgjiHT40NIN4PeVQS9RBh8tOnglsD A6NP0spWxkPPa9M03g9Urt9vZi7kucoj/cAbF41E0oA65+HCxXgEmQG0khar3VulPM YG1DsdVrt/EgWNGgeQDqR4d08eGNFbG6uUhlvFkw= 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 6.12 046/393] umount: Allow superblock owners to force umount Date: Thu, 17 Apr 2025 19:47:35 +0200 Message-ID: <20250417175109.444219302@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250417175107.546547190@linuxfoundation.org> References: <20250417175107.546547190@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 6.12-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 73da51ac5a034..f898de3a6f705 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1986,6 +1986,7 @@ 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; @@ -1995,7 +1996,7 @@ 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