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 B66CC1A3178; Thu, 17 Apr 2025 18:18:36 +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=1744913916; cv=none; b=YePnVViwnHP3fKlgVBrLKY9vXTcqv+2xD6OjiHz2R/nUVdMb9YIS2DlbI6ePWhl9A70tiT0JHGaJynkUE6x7xr510/ntrFMqPaiSc3TC4EQmT1Yva0NBiENk2ffM5tqAuG56SRZDQ+C9Iok9tDCtIDUOP2x2jYOgPEv6mZPVI2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744913916; c=relaxed/simple; bh=/6wP+uCidGuqot0utOd6zMR4OSBWxyW4VnmLvjSXNBc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hdY1fkooky8Ju3XY4GcHCkQHin8X5cglr1Dj8BBvzuDIwI1l9Pat46opmRko9+uukt2JWiI6J2ALzdK2JPSmyEjZfiTLJuKsXqGbP1kbgVBEYm/dsp9wpPtpKaV7A8iIj4oEioutTQ/lbF2tT0k2UVAM1WRDPt0bx4wBa2N403I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=orFBX8Vn; 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="orFBX8Vn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41C1DC4CEE7; Thu, 17 Apr 2025 18:18:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744913916; bh=/6wP+uCidGuqot0utOd6zMR4OSBWxyW4VnmLvjSXNBc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=orFBX8Vn2/GN+0eAcDvTqUY64DSFywivgOGDh63CRv6mLYWihcBMqFp/BypefAa01 dfNrybpP2717smzf6mPEq6hVTP4JJAJXthrw+JXqDcivaASTaWtq1ZAA7VLjFswitn o1CjxhdMvHl0NqzM9rzVPn3w0GVIUYXE45rwQ2U0= 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 6.13 043/414] umount: Allow superblock owners to force umount Date: Thu, 17 Apr 2025 19:46:41 +0200 Message-ID: <20250417175113.146680752@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250417175111.386381660@linuxfoundation.org> References: <20250417175111.386381660@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.13-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 cb08db40fc039..6a22882d5f54c 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