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 99C661DA60C; Tue, 8 Oct 2024 12:31:18 +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=1728390678; cv=none; b=evw8d1Mjp50CShiFq1/dp4/9M1BmJGsOzC7oBgPO8UEUcncUFwxuCu1CU9dL1vHbiarOYkDHtH2Y20EJldVDzTjMZSLeZYsluLlaUslnqjEv+TcRXAtyqwepppZqOvoQIixiQe5agWN17urVKL4JE7U1Y0drZHhvnJTO4zigvc4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728390678; c=relaxed/simple; bh=vsBnl3nvi4sq01MJNMjEz6ctp5bmhPtT4oCeEKxSI1Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mlZwjElJMD+8TxbWd0g7f+UhhBkxzK4+ViLGN4ficPzDq8cftcPkkw4pcNirdyQX2ia55nANQcw1uWjmiv3obxJLWGJ9Yxof1s0LSU1W5Ck3mFdcNWZcOkwsQHdZ7Xp0FFlRNDv3ApHujou7XzZg2anDz/e0PSH0DCwhp/0HYTo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PtSz3IQ0; 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="PtSz3IQ0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A9C3C4CEC7; Tue, 8 Oct 2024 12:31:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728390678; bh=vsBnl3nvi4sq01MJNMjEz6ctp5bmhPtT4oCeEKxSI1Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PtSz3IQ06c1EQl/A4Mzqw4nWtUlWpW13W0ShPW9zSeHtAmavmjXxS97L+7uN7W+XA SKXFBms54inv5J/eX/WYtWz3wXlRYZ1pmwJiYGDqPqCWwrXl36ctUqROi1/fPJ8zdr cwRH3iS9oO5csTgpdIAPmFylLjbLh8+d8Om0xUD8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, Baokun Li , Jan Kara , Ojaswin Mujoo , Theodore Tso Subject: [PATCH 6.10 329/482] ext4: drop ppath from ext4_ext_replay_update_ex() to avoid double-free Date: Tue, 8 Oct 2024 14:06:32 +0200 Message-ID: <20241008115701.374170016@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115648.280954295@linuxfoundation.org> References: <20241008115648.280954295@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li commit 5c0f4cc84d3a601c99bc5e6e6eb1cbda542cce95 upstream. When calling ext4_force_split_extent_at() in ext4_ext_replay_update_ex(), the 'ppath' is updated but it is the 'path' that is freed, thus potentially triggering a double-free in the following process: ext4_ext_replay_update_ex ppath = path ext4_force_split_extent_at(&ppath) ext4_split_extent_at ext4_ext_insert_extent ext4_ext_create_new_leaf ext4_ext_grow_indepth ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path) ---> path First freed *orig_path = path = NULL ---> null ppath kfree(path) ---> path double-free !!! So drop the unnecessary ppath and use path directly to avoid this problem. And use ext4_find_extent() directly to update path, avoiding unnecessary memory allocation and freeing. Also, propagate the error returned by ext4_find_extent() instead of using strange error codes. Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Cc: stable@kernel.org Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Ojaswin Mujoo Tested-by: Ojaswin Mujoo Link: https://patch.msgid.link/20240822023545.1994557-8-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/extents.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -5899,7 +5899,7 @@ out: int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start, int len, int unwritten, ext4_fsblk_t pblk) { - struct ext4_ext_path *path = NULL, *ppath; + struct ext4_ext_path *path; struct ext4_extent *ex; int ret; @@ -5915,30 +5915,29 @@ int ext4_ext_replay_update_ex(struct ino if (le32_to_cpu(ex->ee_block) != start || ext4_ext_get_actual_len(ex) != len) { /* We need to split this extent to match our extent first */ - ppath = path; down_write(&EXT4_I(inode)->i_data_sem); - ret = ext4_force_split_extent_at(NULL, inode, &ppath, start, 1); + ret = ext4_force_split_extent_at(NULL, inode, &path, start, 1); up_write(&EXT4_I(inode)->i_data_sem); if (ret) goto out; - kfree(path); - path = ext4_find_extent(inode, start, NULL, 0); + + path = ext4_find_extent(inode, start, &path, 0); if (IS_ERR(path)) - return -1; - ppath = path; + return PTR_ERR(path); ex = path[path->p_depth].p_ext; WARN_ON(le32_to_cpu(ex->ee_block) != start); + if (ext4_ext_get_actual_len(ex) != len) { down_write(&EXT4_I(inode)->i_data_sem); - ret = ext4_force_split_extent_at(NULL, inode, &ppath, + ret = ext4_force_split_extent_at(NULL, inode, &path, start + len, 1); up_write(&EXT4_I(inode)->i_data_sem); if (ret) goto out; - kfree(path); - path = ext4_find_extent(inode, start, NULL, 0); + + path = ext4_find_extent(inode, start, &path, 0); if (IS_ERR(path)) - return -EINVAL; + return PTR_ERR(path); ex = path[path->p_depth].p_ext; } }