From patchwork Mon Nov 2 17:27:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 11874681 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 08DF992C for ; Mon, 2 Nov 2020 17:27:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E646E222BA for ; Mon, 2 Nov 2020 17:27:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727478AbgKBR1k (ORCPT ); Mon, 2 Nov 2020 12:27:40 -0500 Received: from mx2.suse.de ([195.135.220.15]:49882 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727288AbgKBR1j (ORCPT ); Mon, 2 Nov 2020 12:27:39 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 0F4CEB2CB; Mon, 2 Nov 2020 17:27:38 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 822B11E1303; Mon, 2 Nov 2020 18:27:37 +0100 (CET) From: Jan Kara To: Cc: Jan Kara , stable@vger.kernel.org Subject: [PATCH 2/2] quota: Sanity-check quota file headers on load Date: Mon, 2 Nov 2020 18:27:33 +0100 Message-Id: <20201102172733.23444-3-jack@suse.cz> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20201102172733.23444-1-jack@suse.cz> References: <20201102172733.23444-1-jack@suse.cz> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Perform basic sanity checks of quota headers to avoid kernel crashes on corrupted quota files. CC: stable@vger.kernel.org Reported-by: syzbot+f816042a7ae2225f25ba@syzkaller.appspotmail.com Signed-off-by: Jan Kara Reviewed-by: Andreas Dilger --- fs/quota/quota_v2.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c index e69a2bfdd81c..c21106557a37 100644 --- a/fs/quota/quota_v2.c +++ b/fs/quota/quota_v2.c @@ -157,6 +157,25 @@ static int v2_read_file_info(struct super_block *sb, int type) qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk); qinfo->dqi_ops = &v2r1_qtree_ops; } + ret = -EUCLEAN; + /* Some sanity checks of the read headers... */ + if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits > + i_size_read(sb_dqopt(sb)->files[type])) { + quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).", + (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits, + i_size_read(sb_dqopt(sb)->files[type])); + goto out; + } + if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) { + quota_error(sb, "Free block number too big (%u >= %u).", + qinfo->dqi_free_blk, qinfo->dqi_blocks); + goto out; + } + if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) { + quota_error(sb, "Block with free entry too big (%u >= %u).", + qinfo->dqi_free_entry, qinfo->dqi_blocks); + goto out; + } ret = 0; out: up_read(&dqopt->dqio_sem);