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 DA0B71714D0; Thu, 15 Aug 2024 13:32:16 +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=1723728736; cv=none; b=Zwm3Qa1ZSDVjyzPhErJbPjMHmYy8qXtIihReN9huFhlh0KYYyGc2J1JdEjK40Q0mptsmsPsc4Fpn6wW6DJkKMINWIQnaECn1vpN0ijJ3fVQKcggQci6quK9K0DQnfEkwogdKLv9fOH8247bWL0EQxYACYQTCwHB5O1c0PFcPdm8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723728736; c=relaxed/simple; bh=gHTYCWXrn0rmtoM3Z+ImNjGdB7dKPfgFqwAXl7i/PWc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=L7ee805Zlh6ZN/qv0xNc0FNFYA47JDv+EWGO0IpuDiWJI6x97sDycKq8Hj13Z6D1H/WChjnQmdqiKNytdElQEAMLsu2eCDnDOrpK2HYVoG+BA5zStUbX0vvFu6cr4ZHvvEQpTk8V/0vW3EEDuL69Do5Gbez3rfHFV2vCZQSce0w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=urOqXlSk; 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="urOqXlSk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60000C32786; Thu, 15 Aug 2024 13:32:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723728736; bh=gHTYCWXrn0rmtoM3Z+ImNjGdB7dKPfgFqwAXl7i/PWc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=urOqXlSkqGaEuQ6NwUdIgEo5lm/mKPpVHcGP+H9FqnH0Q+qBpwFaaTZnt7sqiBeS2 vh2OGJaR0+tcBHrKPLQ9HOOaTwQ1w+cSdIH42ZjHrqR7YJzcm7Dn+nrW0WVh+dTMgl h9k2IlqQTff5o2mr2DJOd1YYTVvn6owVodjg3cVI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , syzbot+89cc4f2324ed37988b60@syzkaller.appspotmail.com, Andrew Morton Subject: [PATCH 4.19 094/196] nilfs2: handle inconsistent state in nilfs_btnode_create_block() Date: Thu, 15 Aug 2024 15:23:31 +0200 Message-ID: <20240815131855.679080744@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240815131852.063866671@linuxfoundation.org> References: <20240815131852.063866671@linuxfoundation.org> User-Agent: quilt/0.67 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ryusuke Konishi commit 4811f7af6090e8f5a398fbdd766f903ef6c0d787 upstream. Syzbot reported that a buffer state inconsistency was detected in nilfs_btnode_create_block(), triggering a kernel bug. It is not appropriate to treat this inconsistency as a bug; it can occur if the argument block address (the buffer index of the newly created block) is a virtual block number and has been reallocated due to corruption of the bitmap used to manage its allocation state. So, modify nilfs_btnode_create_block() and its callers to treat it as a possible filesystem error, rather than triggering a kernel bug. Link: https://lkml.kernel.org/r/20240725052007.4562-1-konishi.ryusuke@gmail.com Fixes: a60be987d45d ("nilfs2: B-tree node cache") Signed-off-by: Ryusuke Konishi Reported-by: syzbot+89cc4f2324ed37988b60@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=89cc4f2324ed37988b60 Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/btnode.c | 25 ++++++++++++++++++++----- fs/nilfs2/btree.c | 4 ++-- 2 files changed, 22 insertions(+), 7 deletions(-) --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -51,12 +51,21 @@ nilfs_btnode_create_block(struct address bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node)); if (unlikely(!bh)) - return NULL; + return ERR_PTR(-ENOMEM); if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) || buffer_dirty(bh))) { - brelse(bh); - BUG(); + /* + * The block buffer at the specified new address was already + * in use. This can happen if it is a virtual block number + * and has been reallocated due to corruption of the bitmap + * used to manage its allocation state (if not, the buffer + * clearing of an abandoned b-tree node is missing somewhere). + */ + nilfs_error(inode->i_sb, + "state inconsistency probably due to duplicate use of b-tree node block address %llu (ino=%lu)", + (unsigned long long)blocknr, inode->i_ino); + goto failed; } memset(bh->b_data, 0, i_blocksize(inode)); bh->b_bdev = inode->i_sb->s_bdev; @@ -67,6 +76,12 @@ nilfs_btnode_create_block(struct address unlock_page(bh->b_page); put_page(bh->b_page); return bh; + +failed: + unlock_page(bh->b_page); + put_page(bh->b_page); + brelse(bh); + return ERR_PTR(-EIO); } int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, @@ -224,8 +239,8 @@ retry: } nbh = nilfs_btnode_create_block(btnc, newkey); - if (!nbh) - return -ENOMEM; + if (IS_ERR(nbh)) + return PTR_ERR(nbh); BUG_ON(nbh == obh); ctxt->newbh = nbh; --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -63,8 +63,8 @@ static int nilfs_btree_get_new_block(con struct buffer_head *bh; bh = nilfs_btnode_create_block(btnc, ptr); - if (!bh) - return -ENOMEM; + if (IS_ERR(bh)) + return PTR_ERR(bh); set_buffer_nilfs_volatile(bh); *bhp = bh;