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 A92881D5AD7; Wed, 6 Nov 2024 12:10:21 +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=1730895021; cv=none; b=X5qqRLaGaZRUL38IkWGlIx6FTWw8brkTT38iRCrSRT0Mx1F3UDo+WzvHuOfE161hkuTwYXoZnq6EgmzMgcOPXaFlLRD1U6GqkEEl70NgjOdeMdXIzb3OqGyf9/a1CckgRC23CP/sMxb78DfMTViLTgpGdvoy/mqoW+Ojs5gdQO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730895021; c=relaxed/simple; bh=BqGcA7IliecmaTaj9tw36B5DBsUKR57b/5eiwz2gGyg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Pjio3SBxD4wswAXby0EC7CzwAk4jDyPWpShWYZNjpZb5dtW0oNuF9GTdvAT7+VWRRZrzA7Os4Z3dcWKtp8qv1KYaMtMpJ7Qjan1QWs/xhetq3isJqejBU/q7xOKzoKg370prvj7P7NOmBnl6AOMXUuZJ3n5/JMy9FGgZ5tB2hcY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=D3ZI563I; 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="D3ZI563I" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9DF0C4CECD; Wed, 6 Nov 2024 12:10:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730895021; bh=BqGcA7IliecmaTaj9tw36B5DBsUKR57b/5eiwz2gGyg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D3ZI563IWZ6VjQHjmgrvLw340hLFyE9cipBYC3UnHH2WPkoyPxIbORAKhRgu8FiE1 AydhWuhV+na9uO5gmIivwoMdfSfFK3nc0fhhQTXFityzJKAzwExue1UguBMn0xcHmj 7QF9d1Obq3/6aWiAncfhlN8xBO8+S5E2KAAfm3fA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , Lizhi Xu , Andrew Morton , Sasha Levin Subject: [PATCH 4.19 078/350] nilfs2: fix potential oob read in nilfs_btree_check_delete() Date: Wed, 6 Nov 2024 13:00:06 +0100 Message-ID: <20241106120322.821071471@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120320.865793091@linuxfoundation.org> References: <20241106120320.865793091@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 [ Upstream commit f9c96351aa6718b42a9f42eaf7adce0356bdb5e8 ] The function nilfs_btree_check_delete(), which checks whether degeneration to direct mapping occurs before deleting a b-tree entry, causes memory access outside the block buffer when retrieving the maximum key if the root node has no entries. This does not usually happen because b-tree mappings with 0 child nodes are never created by mkfs.nilfs2 or nilfs2 itself. However, it can happen if the b-tree root node read from a device is configured that way, so fix this potential issue by adding a check for that case. Link: https://lkml.kernel.org/r/20240904081401.16682-4-konishi.ryusuke@gmail.com Fixes: 17c76b0104e4 ("nilfs2: B-tree based block mapping") Signed-off-by: Ryusuke Konishi Cc: Lizhi Xu Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- fs/nilfs2/btree.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index 7cfff27b4b4a5..7c9f4d79bdbc5 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -1660,13 +1660,16 @@ static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key) int nchildren, ret; root = nilfs_btree_get_root(btree); + nchildren = nilfs_btree_node_get_nchildren(root); + if (unlikely(nchildren == 0)) + return 0; + switch (nilfs_btree_height(btree)) { case 2: bh = NULL; node = root; break; case 3: - nchildren = nilfs_btree_node_get_nchildren(root); if (nchildren > 1) return 0; ptr = nilfs_btree_node_get_ptr(root, nchildren - 1, @@ -1675,12 +1678,12 @@ static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key) if (ret < 0) return ret; node = (struct nilfs_btree_node *)bh->b_data; + nchildren = nilfs_btree_node_get_nchildren(node); break; default: return 0; } - nchildren = nilfs_btree_node_get_nchildren(node); maxkey = nilfs_btree_node_get_key(node, nchildren - 1); nextmaxkey = (nchildren > 1) ? nilfs_btree_node_get_key(node, nchildren - 2) : 0; -- 2.43.0