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Subject: Re: [PATCH v2] fsck.f2fs: check nid range before use to avoid
 segmentation fault
To: Chao Yu <yuchao0@huawei.com>, <jaegeuk@kernel.org>, <chao@kernel.org>,
        <yunlong.song@icloud.com>
CC: <miaoxie@huawei.com>, <bintian.wang@huawei.com>,
        <shengyong1@huawei.com>, <heyunlei@huawei.com>,
        <linux-fsdevel@vger.kernel.org>,
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        <linux-kernel@vger.kernel.org>
References: <1513319174-114303-1-git-send-email-yunlong.song@huawei.com>
 <1513598025-160615-1-git-send-email-yunlong.song@huawei.com>
 <e912dbdb-3614-cee0-c7f7-2b5f6344466f@huawei.com>
From: Yunlong Song <yunlong.song@huawei.com>
Message-ID: <88632fa0-ec8d-ecf0-656f-c52fbfdc9be2@huawei.com>
Date: Sat, 23 Dec 2017 11:35:50 +0800
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Both are OK, since nid < root_ino cannot trigger segmentation fault 
(nat_block->entries[nid%NAT_ENTRY_PER_BLOCK]).

On 2017/12/23 11:14, Chao Yu wrote:
> On 2017/12/18 19:53, Yunlong Song wrote:
>> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
> How about introducing IS_AVAILABLE_NID as below, and use it instead?
>
> #define IS_AVAILABLE_NID(sbi, nid)	(IS_VALID_NID(sbi, nid) && (nid >= root_ino))
>
> Thanks,
>
>> ---
>>   fsck/fsck.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fsck/fsck.c b/fsck/fsck.c
>> index 11b8b0b..faf0663 100644
>> --- a/fsck/fsck.c
>> +++ b/fsck/fsck.c
>> @@ -740,7 +740,7 @@ void fsck_chk_inode_blk(struct f2fs_sb_info *sbi, u32 nid,
>>   	for (idx = 0; idx < 5; idx++) {
>>   		u32 nid = le32_to_cpu(node_blk->i.i_nid[idx]);
>>   
>> -		if (nid != 0) {
>> +		if (nid != 0 && IS_VALID_NID(sbi, nid)) {
>>   			struct node_info ni;
>>   
>>   			get_node_info(sbi, nid, &ni);
>>
>
> .
>

-- 
Thanks,
Yunlong Song