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 B8F1C1DF26D; Tue, 8 Oct 2024 13:22:06 +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=1728393726; cv=none; b=N5PlOrFw85Oc3UYoFT0p2SwLd1a1YdgcdC+8aLGNFbLPfQ4vuwJneyNp1UPFWokr67XpnTzMV98Sf6fz8yg41xbXjq6cIyO4l8w7u+5FpehCrKH8aGkCSKllDapGhiHpGqnyw1rbIJ11HkPwvwqwfldJUAbI9RSrYufHlhEggZA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728393726; c=relaxed/simple; bh=MjlaM6eV8VjepO21sPXboW3dE7H4AAIX1o5Z4zAiu9A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TVMCTBAngdGloX2nW/xxcvDl7NW67mGXUZoL4XvrLi4Z/IfKCXA7xsVpqPfqdL4h1RTYPhWdW70uLwMFtevzgWUIjpe5OO6KTCv4nsIOAl8oOSzeGGB6D09GAIy55daIWEZOPIWpFt/I34EOigeTacYduESDougJBtYBbszxJIs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EPkN4LIM; 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="EPkN4LIM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1357C4CECC; Tue, 8 Oct 2024 13:22:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728393726; bh=MjlaM6eV8VjepO21sPXboW3dE7H4AAIX1o5Z4zAiu9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EPkN4LIM2kEMnpJnnvXhvQ9egXp1FFJkhwo77m0Cl9wDCfkfL+wTrX20feCriLpYm yCmpCQH5fzDtNiTV+cEzFDQ7pwfqp95I9EEP4wtW4aqIRnLpVzwm1dBbA8+AnLM0jG XGC4f/YX/mk4qSJj+6w9xtEroRuC7MneAaspHZh4= 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 6.6 238/386] ext4: drop ppath from ext4_ext_replay_update_ex() to avoid double-free Date: Tue, 8 Oct 2024 14:08:03 +0200 Message-ID: <20241008115638.764393930@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115629.309157387@linuxfoundation.org> References: <20241008115629.309157387@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 6.6-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 @@ -5895,7 +5895,7 @@ 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; @@ -5911,30 +5911,29 @@ 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; } }