From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) (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 7D569B669; Sat, 27 Jan 2024 02:07:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.255 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706321247; cv=none; b=PU277XjbFnEbzbQLw0WG2K2zQ7LYpc0Zvlsw4LNx55gKv4YjVfCyulV9uud2G8tkgMM2Y1ZR1hpxmlrAuPcKhNBOfpe++hJoyeBHaXKi6zDTdFdlAJFmIanxRwQCNR1Tgm1L1NlCsuEIKnslfFE3R+qqpH+qMczXjnszbtOQtJQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706321247; c=relaxed/simple; bh=D1pPlkWVhGtFEIb+/MVR/16Ou0AZcX23YBF7y5BCQJA=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=HCVc+Eg5axEds50dQOh9aUO4lNR6U2sTsuErwfIriroYIOrChByHGY70txx5WXAdtINEkxNt+GNI6QO41rdzkycuK67zYsLvBGbjGkf0hl442sZ/nxg2Hz2LbKBSauDdahGADgCcL+adWrCCYhh3Wq37Vdnc9rjI/wOOU16uCWs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.255 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.254]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4TMHwj4f5Yz18MJg; Sat, 27 Jan 2024 10:06:13 +0800 (CST) Received: from canpemm500005.china.huawei.com (unknown [7.192.104.229]) by mail.maildlp.com (Postfix) with ESMTPS id C307118001C; Sat, 27 Jan 2024 10:07:19 +0800 (CST) Received: from [10.174.176.34] (10.174.176.34) by canpemm500005.china.huawei.com (7.192.104.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Sat, 27 Jan 2024 10:07:19 +0800 Subject: Re: [PATCH 4/7] ext4: add positive int attr pointer to avoid sysfs variables overflow To: Baokun Li , CC: , , , , , , , , References: <20240126085716.1363019-1-libaokun1@huawei.com> <20240126085716.1363019-5-libaokun1@huawei.com> From: Zhang Yi Message-ID: <864b67a3-6a4a-2afb-8275-b8532ea3cb8f@huawei.com> Date: Sat, 27 Jan 2024 10:07:18 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20240126085716.1363019-5-libaokun1@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500005.china.huawei.com (7.192.104.229) On 2024/1/26 16:57, Baokun Li wrote: > We can easily trigger a BUG_ON by using the following commands: > > mount /dev/$disk /tmp/test > echo 2147483650 > /sys/fs/ext4/$disk/mb_group_prealloc > echo test > /tmp/test/file && sync > > ================================================================== > kernel BUG at fs/ext4/mballoc.c:2029! > invalid opcode: 0000 [#1] PREEMPT SMP PTI > CPU: 3 PID: 320 Comm: kworker/u36:1 Not tainted 6.8.0-rc1 #462 > RIP: 0010:mb_mark_used+0x358/0x370 > [...] > Call Trace: > ext4_mb_use_best_found+0x56/0x140 > ext4_mb_complex_scan_group+0x196/0x2f0 > ext4_mb_regular_allocator+0xa92/0xf00 > ext4_mb_new_blocks+0x302/0xbc0 > ext4_ext_map_blocks+0x95a/0xef0 > ext4_map_blocks+0x2b1/0x680 > ext4_do_writepages+0x733/0xbd0 > [...] > ================================================================== > > In ext4_mb_normalize_group_request(): > ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; > > Here fe_len is of type int, but s_mb_group_prealloc is of type unsigned > int, so setting s_mb_group_prealloc to 2147483650 overflows fe_len to a > negative number, which ultimately triggers a BUG_ON() in mb_mark_used(). > > Therefore, we add attr_pointer_pi (aka positive int attr pointer) with a > value range of 0-INT_MAX to avoid the above problem. In addition to the > mb_group_prealloc sysfs interface, the following interfaces also have uint > to int conversions that result in overflows, and are also fixed. > > err_ratelimit_burst > msg_ratelimit_burst > warning_ratelimit_burst > err_ratelimit_interval_ms > msg_ratelimit_interval_ms > warning_ratelimit_interval_ms > mb_best_avail_max_trim_order > > CC: stable@vger.kernel.org > Signed-off-by: Baokun Li Looks good to me. Reviewed-by: Zhang Yi > --- > fs/ext4/sysfs.c | 25 +++++++++++++++++-------- > 1 file changed, 17 insertions(+), 8 deletions(-) > > diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c > index a5d657fa05cb..6f9f96e00f2f 100644 > --- a/fs/ext4/sysfs.c > +++ b/fs/ext4/sysfs.c > @@ -30,6 +30,7 @@ typedef enum { > attr_first_error_time, > attr_last_error_time, > attr_feature, > + attr_pointer_pi, > attr_pointer_ui, > attr_pointer_ul, > attr_pointer_u64, > @@ -178,6 +179,9 @@ static struct ext4_attr ext4_attr_##_name = { \ > #define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size) \ > EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname) > > +#define EXT4_RW_ATTR_SBI_PI(_name,_elname) \ > + EXT4_ATTR_OFFSET(_name, 0644, pointer_pi, ext4_sb_info, _elname) > + > #define EXT4_RW_ATTR_SBI_UI(_name,_elname) \ > EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname) > > @@ -213,17 +217,17 @@ EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan); > EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan); > EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs); > EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request); > -EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc); > +EXT4_RW_ATTR_SBI_PI(mb_group_prealloc, s_mb_group_prealloc); > EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups); > EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb); > EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error); > -EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval); > -EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst); > -EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval); > -EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst); > -EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval); > -EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst); > -EXT4_RW_ATTR_SBI_UI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order); > +EXT4_RW_ATTR_SBI_PI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval); > +EXT4_RW_ATTR_SBI_PI(err_ratelimit_burst, s_err_ratelimit_state.burst); > +EXT4_RW_ATTR_SBI_PI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval); > +EXT4_RW_ATTR_SBI_PI(warning_ratelimit_burst, s_warning_ratelimit_state.burst); > +EXT4_RW_ATTR_SBI_PI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval); > +EXT4_RW_ATTR_SBI_PI(msg_ratelimit_burst, s_msg_ratelimit_state.burst); > +EXT4_RW_ATTR_SBI_PI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order); > #ifdef CONFIG_EXT4_DEBUG > EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail); > #endif > @@ -376,6 +380,7 @@ static ssize_t ext4_generic_attr_show(struct ext4_attr *a, > > switch (a->attr_id) { > case attr_inode_readahead: > + case attr_pointer_pi: > case attr_pointer_ui: > if (a->attr_ptr == ptr_ext4_super_block_offset) > return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr)); > @@ -448,6 +453,10 @@ static ssize_t ext4_generic_attr_store(struct ext4_attr *a, > return ret; > > switch (a->attr_id) { > + case attr_pointer_pi: > + if ((int)t < 0) > + return -EINVAL; > + fallthrough; > case attr_pointer_ui: > if (t != (unsigned int)t) > return -EINVAL; >