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 E13F2C433DF for ; Tue, 26 May 2020 19:33:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE79120776 for ; Tue, 26 May 2020 19:33:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590521639; bh=eMtE+JBaMmlzLtICDuGyHLpacDpmAxayQKApB2U+tyI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RwoYSmqFlQXxUhdNcLT3L7QIrL3Ca12vIX17FIBya3aTagiRCUPu1qdEBlotYbUiK 3Sa//UPLzP5qV9q5wJ4iKB0nqiOOQ3O5QAzY51VYg9nJw0DwW5ASZk9+2AuXhvyvs1 l4opzm18YgNgbcZGxNHo2TRToVAsTCFH8oAx06mY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389630AbgEZSzq (ORCPT ); Tue, 26 May 2020 14:55:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:48258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389600AbgEZSzq (ORCPT ); Tue, 26 May 2020 14:55:46 -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 B21452086A; Tue, 26 May 2020 18:55:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519345; bh=eMtE+JBaMmlzLtICDuGyHLpacDpmAxayQKApB2U+tyI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C8Aa2Wz/DuWTZ6lS80+3+ywk8anX5gMH7bUF14dvaJcJMVD0mO3SZeCwNAhvpUzeq 672RfLB2XD38NbhRGUSgPGAPJuVFbqv5zCUzjTLKFf1hgcPTP1AjPfoNKX3x1sd9gW XcY+o9mD9cXWXvxrLfuCeVootN74omv4ypXMKSFw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Theodore Tso , Sultan Alsawaf Subject: [PATCH 4.4 31/65] ext4: lock the xattr block before checksuming it Date: Tue, 26 May 2020 20:52:50 +0200 Message-Id: <20200526183917.592537446@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183905.988782958@linuxfoundation.org> References: <20200526183905.988782958@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Theodore Ts'o commit dac7a4b4b1f664934e8b713f529b629f67db313c upstream. We must lock the xattr block before calculating or verifying the checksum in order to avoid spurious checksum failures. https://bugzilla.kernel.org/show_bug.cgi?id=193661 Reported-by: Colin Ian King Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Sultan Alsawaf Signed-off-by: Greg Kroah-Hartman --- fs/ext4/xattr.c | 66 +++++++++++++++++++++++++++----------------------------- 1 file changed, 32 insertions(+), 34 deletions(-) --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -139,31 +139,26 @@ static __le32 ext4_xattr_block_csum(stru } static int ext4_xattr_block_csum_verify(struct inode *inode, - sector_t block_nr, - struct ext4_xattr_header *hdr) + struct buffer_head *bh) { - if (ext4_has_metadata_csum(inode->i_sb) && - (hdr->h_checksum != ext4_xattr_block_csum(inode, block_nr, hdr))) - return 0; - return 1; -} - -static void ext4_xattr_block_csum_set(struct inode *inode, - sector_t block_nr, - struct ext4_xattr_header *hdr) -{ - if (!ext4_has_metadata_csum(inode->i_sb)) - return; + struct ext4_xattr_header *hdr = BHDR(bh); + int ret = 1; - hdr->h_checksum = ext4_xattr_block_csum(inode, block_nr, hdr); + if (ext4_has_metadata_csum(inode->i_sb)) { + lock_buffer(bh); + ret = (hdr->h_checksum == ext4_xattr_block_csum(inode, + bh->b_blocknr, hdr)); + unlock_buffer(bh); + } + return ret; } -static inline int ext4_handle_dirty_xattr_block(handle_t *handle, - struct inode *inode, - struct buffer_head *bh) +static void ext4_xattr_block_csum_set(struct inode *inode, + struct buffer_head *bh) { - ext4_xattr_block_csum_set(inode, bh->b_blocknr, BHDR(bh)); - return ext4_handle_dirty_metadata(handle, inode, bh); + if (ext4_has_metadata_csum(inode->i_sb)) + BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode, + bh->b_blocknr, BHDR(bh)); } static inline const struct xattr_handler * @@ -226,7 +221,7 @@ ext4_xattr_check_block(struct inode *ino if (buffer_verified(bh)) return 0; - if (!ext4_xattr_block_csum_verify(inode, bh->b_blocknr, BHDR(bh))) + if (!ext4_xattr_block_csum_verify(inode, bh)) return -EFSBADCRC; error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size, bh->b_data); @@ -590,23 +585,23 @@ ext4_xattr_release_block(handle_t *handl le32_add_cpu(&BHDR(bh)->h_refcount, -1); if (ce) mb_cache_entry_release(ce); + + ext4_xattr_block_csum_set(inode, bh); /* * Beware of this ugliness: Releasing of xattr block references * from different inodes can race and so we have to protect * from a race where someone else frees the block (and releases * its journal_head) before we are done dirtying the buffer. In * nojournal mode this race is harmless and we actually cannot - * call ext4_handle_dirty_xattr_block() with locked buffer as + * call ext4_handle_dirty_metadata() with locked buffer as * that function can call sync_dirty_buffer() so for that case * we handle the dirtying after unlocking the buffer. */ if (ext4_handle_valid(handle)) - error = ext4_handle_dirty_xattr_block(handle, inode, - bh); + error = ext4_handle_dirty_metadata(handle, inode, bh); unlock_buffer(bh); if (!ext4_handle_valid(handle)) - error = ext4_handle_dirty_xattr_block(handle, inode, - bh); + error = ext4_handle_dirty_metadata(handle, inode, bh); if (IS_SYNC(inode)) ext4_handle_sync(handle); dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); @@ -837,13 +832,14 @@ ext4_xattr_block_set(handle_t *handle, s ext4_xattr_rehash(header(s->base), s->here); } + ext4_xattr_block_csum_set(inode, bs->bh); unlock_buffer(bs->bh); if (error == -EFSCORRUPTED) goto bad_block; if (!error) - error = ext4_handle_dirty_xattr_block(handle, - inode, - bs->bh); + error = ext4_handle_dirty_metadata(handle, + inode, + bs->bh); if (error) goto cleanup; goto inserted; @@ -912,10 +908,11 @@ inserted: le32_add_cpu(&BHDR(new_bh)->h_refcount, 1); ea_bdebug(new_bh, "reusing; refcount now=%d", le32_to_cpu(BHDR(new_bh)->h_refcount)); + ext4_xattr_block_csum_set(inode, new_bh); unlock_buffer(new_bh); - error = ext4_handle_dirty_xattr_block(handle, - inode, - new_bh); + error = ext4_handle_dirty_metadata(handle, + inode, + new_bh); if (error) goto cleanup_dquot; } @@ -965,11 +962,12 @@ getblk_failed: goto getblk_failed; } memcpy(new_bh->b_data, s->base, new_bh->b_size); + ext4_xattr_block_csum_set(inode, new_bh); set_buffer_uptodate(new_bh); unlock_buffer(new_bh); ext4_xattr_cache_insert(ext4_mb_cache, new_bh); - error = ext4_handle_dirty_xattr_block(handle, - inode, new_bh); + error = ext4_handle_dirty_metadata(handle, inode, + new_bh); if (error) goto cleanup; }