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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25003C4332F for ; Mon, 6 Nov 2023 13:21:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232413AbjKFNVk (ORCPT ); Mon, 6 Nov 2023 08:21:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232318AbjKFNVj (ORCPT ); Mon, 6 Nov 2023 08:21:39 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE007BF for ; Mon, 6 Nov 2023 05:21:36 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2F1CC433C7; Mon, 6 Nov 2023 13:21:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1699276896; bh=7NE5UrnJBzIOjqgukOrhrPof7M/Za7OzwbDxKg0d4Eo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ARAPWB9vUL6gZ5IrJHfm04zzwEcXHWdMbqULIE/LVt3CDLQwqG6JgcW84PvuJJmog EtdBdlyhJELF6f09uiUGVc9WeAW9/HTwrp4HyiCp0TyD4KQHytNuD98eZ0GEYGqyRS Gtu72737g6ddHlPu5vD/+SVQ3DdCK/x2RHgScyLw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Baokun Li , "Ritesh Harjani (IBM)" , Theodore Tso , stable@kernel.org Subject: [PATCH 5.4 43/74] ext4: fix BUG in ext4_mb_new_inode_pa() due to overflow Date: Mon, 6 Nov 2023 14:04:03 +0100 Message-ID: <20231106130303.227585695@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231106130301.687882731@linuxfoundation.org> References: <20231106130301.687882731@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li commit bc056e7163ac7db945366de219745cf94f32a3e6 upstream. When we calculate the end position of ext4_free_extent, this position may be exactly where ext4_lblk_t (i.e. uint) overflows. For example, if ac_g_ex.fe_logical is 4294965248 and ac_orig_goal_len is 2048, then the computed end is 0x100000000, which is 0. If ac->ac_o_ex.fe_logical is not the first case of adjusting the best extent, that is, new_bex_end > 0, the following BUG_ON will be triggered: ========================================================= kernel BUG at fs/ext4/mballoc.c:5116! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 673 Comm: xfs_io Tainted: G E 6.5.0-rc1+ #279 RIP: 0010:ext4_mb_new_inode_pa+0xc5/0x430 Call Trace: ext4_mb_use_best_found+0x203/0x2f0 ext4_mb_try_best_found+0x163/0x240 ext4_mb_regular_allocator+0x158/0x1550 ext4_mb_new_blocks+0x86a/0xe10 ext4_ext_map_blocks+0xb0c/0x13a0 ext4_map_blocks+0x2cd/0x8f0 ext4_iomap_begin+0x27b/0x400 iomap_iter+0x222/0x3d0 __iomap_dio_rw+0x243/0xcb0 iomap_dio_rw+0x16/0x80 ========================================================= A simple reproducer demonstrating the problem: mkfs.ext4 -F /dev/sda -b 4096 100M mount /dev/sda /tmp/test fallocate -l1M /tmp/test/tmp fallocate -l10M /tmp/test/file fallocate -i -o 1M -l16777203M /tmp/test/file fsstress -d /tmp/test -l 0 -n 100000 -p 8 & sleep 10 && killall -9 fsstress rm -f /tmp/test/tmp xfs_io -c "open -ad /tmp/test/file" -c "pwrite -S 0xff 0 8192" We simply refactor the logic for adjusting the best extent by adding a temporary ext4_free_extent ex and use extent_logical_end() to avoid overflow, which also simplifies the code. Cc: stable@kernel.org # 6.4 Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()") Signed-off-by: Baokun Li Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230724121059.11834-3-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Baokun Li Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3680,8 +3680,11 @@ ext4_mb_new_inode_pa(struct ext4_allocat return -ENOMEM; if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) { - int new_bex_start; - int new_bex_end; + struct ext4_free_extent ex = { + .fe_logical = ac->ac_g_ex.fe_logical, + .fe_len = ac->ac_g_ex.fe_len, + }; + loff_t orig_goal_end = extent_logical_end(sbi, &ex); /* we can't allocate as much as normalizer wants. * so, found space must get proper lstart @@ -3700,29 +3703,23 @@ ext4_mb_new_inode_pa(struct ext4_allocat * still cover original start * 3. Else, keep the best ex at start of original request. */ - new_bex_end = ac->ac_g_ex.fe_logical + - EXT4_C2B(sbi, ac->ac_g_ex.fe_len); - new_bex_start = new_bex_end - EXT4_C2B(sbi, ac->ac_b_ex.fe_len); - if (ac->ac_o_ex.fe_logical >= new_bex_start) - goto adjust_bex; + ex.fe_len = ac->ac_b_ex.fe_len; - new_bex_start = ac->ac_g_ex.fe_logical; - new_bex_end = - new_bex_start + EXT4_C2B(sbi, ac->ac_b_ex.fe_len); - if (ac->ac_o_ex.fe_logical < new_bex_end) + ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len); + if (ac->ac_o_ex.fe_logical >= ex.fe_logical) goto adjust_bex; - new_bex_start = ac->ac_o_ex.fe_logical; - new_bex_end = - new_bex_start + EXT4_C2B(sbi, ac->ac_b_ex.fe_len); + ex.fe_logical = ac->ac_g_ex.fe_logical; + if (ac->ac_o_ex.fe_logical < extent_logical_end(sbi, &ex)) + goto adjust_bex; + ex.fe_logical = ac->ac_o_ex.fe_logical; adjust_bex: - ac->ac_b_ex.fe_logical = new_bex_start; + ac->ac_b_ex.fe_logical = ex.fe_logical; BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); - BUG_ON(new_bex_end > (ac->ac_g_ex.fe_logical + - EXT4_C2B(sbi, ac->ac_g_ex.fe_len))); + BUG_ON(extent_logical_end(sbi, &ex) > orig_goal_end); } /* preallocation can change ac_b_ex, thus we store actually