From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C40BC10F14 for ; Sun, 6 Oct 2019 17:24:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE79B20867 for ; Sun, 6 Oct 2019 17:24:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382677; bh=fHqOQJ6Mhd47oaOIPunjdLpumaaCH0jkysn3GhZIxdc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WV9z6AwCf9LrBZVTjltr52EhzhWZKEEG+twTrNv9cwDI+ayd0iDFT4E/aXPI/jR6w VF+8YGHtV00/33dkKhl+dDh5N34EEPQ7Yb+uQDXhlfL6CcNLSITTb3JwVoKsYGHjE8 qrs0enjVu51+ph7uX9giVdq1LdPC0daY7IB29gxE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727936AbfJFRYg (ORCPT ); Sun, 6 Oct 2019 13:24:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:49492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727899AbfJFRYd (ORCPT ); Sun, 6 Oct 2019 13:24:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9913F20867; Sun, 6 Oct 2019 17:24:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382673; bh=fHqOQJ6Mhd47oaOIPunjdLpumaaCH0jkysn3GhZIxdc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mhhleIcnxbpSRU6rX4/knKeteegmrhe4euL09lNW35/Dg7RfBya2rl9dUhNirUdqy 0nJvj3J76Wnzz/B4Y1GtKDLatOnhrCtHVCqIlOWRyJduJ3gBYkScjdv3zECeFQo8uc Tn/6iLb8MYPImBg8KIGpc3o5bh3bNrALYyMpwQaw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+0eefc1e06a77d327a056@syzkaller.appspotmail.com, Eric Biggers , Casey Schaufler Subject: [PATCH 4.9 46/47] smack: use GFP_NOFS while holding inode_smack::smk_lock Date: Sun, 6 Oct 2019 19:21:33 +0200 Message-Id: <20191006172019.312676905@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006172016.873463083@linuxfoundation.org> References: <20191006172016.873463083@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Biggers commit e5bfad3d7acc5702f32aafeb388362994f4d7bd0 upstream. inode_smack::smk_lock is taken during smack_d_instantiate(), which is called during a filesystem transaction when creating a file on ext4. Therefore to avoid a deadlock, all code that takes this lock must use GFP_NOFS, to prevent memory reclaim from waiting for the filesystem transaction to complete. Reported-by: syzbot+0eefc1e06a77d327a056@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman --- security/smack/smack_access.c | 4 ++-- security/smack/smack_lsm.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -474,7 +474,7 @@ char *smk_parse_smack(const char *string if (i == 0 || i >= SMK_LONGLABEL) return ERR_PTR(-EINVAL); - smack = kzalloc(i + 1, GFP_KERNEL); + smack = kzalloc(i + 1, GFP_NOFS); if (smack == NULL) return ERR_PTR(-ENOMEM); @@ -545,7 +545,7 @@ struct smack_known *smk_import_entry(con if (skp != NULL) goto freeout; - skp = kzalloc(sizeof(*skp), GFP_KERNEL); + skp = kzalloc(sizeof(*skp), GFP_NOFS); if (skp == NULL) { skp = ERR_PTR(-ENOMEM); goto freeout; --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -268,7 +268,7 @@ static struct smack_known *smk_fetch(con if (!(ip->i_opflags & IOP_XATTR)) return ERR_PTR(-EOPNOTSUPP); - buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL); + buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS); if (buffer == NULL) return ERR_PTR(-ENOMEM);