* Re: [RFC PATCH] mkfs.f2fs: avoid dumplicate extension
2015-11-27 16:55 [RFC PATCH] mkfs.f2fs: avoid dumplicate extension Sheng Yong
@ 2015-11-27 13:09 ` Chao Yu
2015-11-28 0:39 ` Sheng Yong
0 siblings, 1 reply; 5+ messages in thread
From: Chao Yu @ 2015-11-27 13:09 UTC (permalink / raw)
To: Sheng Yong; +Cc: jaegeuk, linux-f2fs-devel
Hi Sheng Yong,
On 11/28/15 12:55 AM, Sheng Yong wrote:
> Before copying user specified extension to extension_list, check if it is
> already in the list.
>
> Signed-off-by: Sheng Yong <shengyong1@huawei.com>
> ---
> mkfs/f2fs_format.c | 23 ++++++++++++++++++++++-
> 1 file changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
> index 176bdea..b7ea19f 100644
> --- a/mkfs/f2fs_format.c
> +++ b/mkfs/f2fs_format.c
> @@ -118,6 +118,26 @@ const char *media_ext_lists[] = {
> NULL
> };
>
> +static int extension_exist(const char *name, const int len)
bool is_extension_exist?
> +{
> + const char **extlist = media_ext_lists;
> + int name_len, min_len;
> + int ret;
> +
> +
> + while (*extlist) {
> + name_len = strlen(*extlist);
> + min_len = name_len < len ? name_len : len;
> + ret = strncmp(*extlist, name, min_len);
How about using strcmp(*extlist, name)? It will return 0 only if the two strings
are the same.
> +
> + if (ret == 0 && name_len == len)
> + return 1;
> + extlist++;
> + }
> +
> + return 0;
> +}
> +
> static void configure_extension_list(void)
> {
> const char **extlist = media_ext_lists;
> @@ -144,7 +164,8 @@ static void configure_extension_list(void)
> ue = strtok(ext_str, ",");
> while (ue != NULL) {
> name_len = strlen(ue);
We should verify the length of extension to avoid memcpy overflow. I will send a
patch for fixing.
> - memcpy(sb.extension_list[i++], ue, name_len);
> + if (!extension_exist(ue, name_len))
How do you think of comparing extension user defined with sb.extension_list?
In this way, duplication user defined can be avoided completely.
Thanks,
> + memcpy(sb.extension_list[i++], ue, name_len);
> ue = strtok(NULL, ",");
> if (i >= F2FS_MAX_EXTENSION)
> break;
>
------------------------------------------------------------------------------
^ permalink raw reply [flat|nested] 5+ messages in thread
* [RFC PATCH] mkfs.f2fs: avoid dumplicate extension
@ 2015-11-27 16:55 Sheng Yong
2015-11-27 13:09 ` Chao Yu
0 siblings, 1 reply; 5+ messages in thread
From: Sheng Yong @ 2015-11-27 16:55 UTC (permalink / raw)
To: chao2.yu, jaegeuk; +Cc: linux-f2fs-devel
Before copying user specified extension to extension_list, check if it is
already in the list.
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
---
mkfs/f2fs_format.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 176bdea..b7ea19f 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -118,6 +118,26 @@ const char *media_ext_lists[] = {
NULL
};
+static int extension_exist(const char *name, const int len)
+{
+ const char **extlist = media_ext_lists;
+ int name_len, min_len;
+ int ret;
+
+
+ while (*extlist) {
+ name_len = strlen(*extlist);
+ min_len = name_len < len ? name_len : len;
+ ret = strncmp(*extlist, name, min_len);
+
+ if (ret == 0 && name_len == len)
+ return 1;
+ extlist++;
+ }
+
+ return 0;
+}
+
static void configure_extension_list(void)
{
const char **extlist = media_ext_lists;
@@ -144,7 +164,8 @@ static void configure_extension_list(void)
ue = strtok(ext_str, ",");
while (ue != NULL) {
name_len = strlen(ue);
- memcpy(sb.extension_list[i++], ue, name_len);
+ if (!extension_exist(ue, name_len))
+ memcpy(sb.extension_list[i++], ue, name_len);
ue = strtok(NULL, ",");
if (i >= F2FS_MAX_EXTENSION)
break;
--
1.9.1
------------------------------------------------------------------------------
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [RFC PATCH] mkfs.f2fs: avoid dumplicate extension
2015-11-27 13:09 ` Chao Yu
@ 2015-11-28 0:39 ` Sheng Yong
2015-11-28 2:31 ` Chao Yu
0 siblings, 1 reply; 5+ messages in thread
From: Sheng Yong @ 2015-11-28 0:39 UTC (permalink / raw)
To: Chao Yu; +Cc: jaegeuk, linux-f2fs-devel
On 11/27/2015 9:09 PM, Chao Yu wrote:
> Hi Sheng Yong,
>
> On 11/28/15 12:55 AM, Sheng Yong wrote:
>> Before copying user specified extension to extension_list, check if it is
>> already in the list.
>>
>> Signed-off-by: Sheng Yong <shengyong1@huawei.com>
>> ---
>> mkfs/f2fs_format.c | 23 ++++++++++++++++++++++-
>> 1 file changed, 22 insertions(+), 1 deletion(-)
>>
>> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
>> index 176bdea..b7ea19f 100644
>> --- a/mkfs/f2fs_format.c
>> +++ b/mkfs/f2fs_format.c
>> @@ -118,6 +118,26 @@ const char *media_ext_lists[] = {
>> NULL
>> };
>>
>> +static int extension_exist(const char *name, const int len)
>
> bool is_extension_exist?
>
>> +{
>> + const char **extlist = media_ext_lists;
>> + int name_len, min_len;
>> + int ret;
>> +
>> +
>> + while (*extlist) {
>> + name_len = strlen(*extlist);
>> + min_len = name_len < len ? name_len : len;
>> + ret = strncmp(*extlist, name, min_len);
>
> How about using strcmp(*extlist, name)? It will return 0 only if the two strings
> are the same.
>
Hi, Chao Yu
Thanks for your reply. I was considering strcmp may have security issue.
>> +
>> + if (ret == 0 && name_len == len)
>> + return 1;
>> + extlist++;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> static void configure_extension_list(void)
>> {
>> const char **extlist = media_ext_lists;
>> @@ -144,7 +164,8 @@ static void configure_extension_list(void)
>> ue = strtok(ext_str, ",");
>> while (ue != NULL) {
>> name_len = strlen(ue);
>
> We should verify the length of extension to avoid memcpy overflow. I will send a
> patch for fixing.
I agree. And I think we should make sure there is a '\0' at the end of each string
in extension_list.
>
>> - memcpy(sb.extension_list[i++], ue, name_len);
>> + if (!extension_exist(ue, name_len))
>
> How do you think of comparing extension user defined with sb.extension_list?
> In this way, duplication user defined can be avoided completely.
Right. I'll send a v2 latter.
thanks,
Sheng
>
> Thanks,
>
>> + memcpy(sb.extension_list[i++], ue, name_len);
>> ue = strtok(NULL, ",");
>> if (i >= F2FS_MAX_EXTENSION)
>> break;
>>
>
> .
>
------------------------------------------------------------------------------
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC PATCH] mkfs.f2fs: avoid dumplicate extension
2015-11-28 0:39 ` Sheng Yong
@ 2015-11-28 2:31 ` Chao Yu
2015-11-28 2:45 ` Sheng Yong
0 siblings, 1 reply; 5+ messages in thread
From: Chao Yu @ 2015-11-28 2:31 UTC (permalink / raw)
To: Sheng Yong; +Cc: jaegeuk, linux-f2fs-devel
Hi Sheng Yong,
On 11/28/15 8:39 AM, Sheng Yong wrote:
>
> On 11/27/2015 9:09 PM, Chao Yu wrote:
>> Hi Sheng Yong,
>>
>> On 11/28/15 12:55 AM, Sheng Yong wrote:
>>> Before copying user specified extension to extension_list, check if it is
>>> already in the list.
>>>
>>> Signed-off-by: Sheng Yong <shengyong1@huawei.com>
>>> ---
>>> mkfs/f2fs_format.c | 23 ++++++++++++++++++++++-
>>> 1 file changed, 22 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
>>> index 176bdea..b7ea19f 100644
>>> --- a/mkfs/f2fs_format.c
>>> +++ b/mkfs/f2fs_format.c
>>> @@ -118,6 +118,26 @@ const char *media_ext_lists[] = {
>>> NULL
>>> };
>>>
>>> +static int extension_exist(const char *name, const int len)
>>
>> bool is_extension_exist?
>>
>>> +{
>>> + const char **extlist = media_ext_lists;
>>> + int name_len, min_len;
>>> + int ret;
>>> +
>>> +
>>> + while (*extlist) {
>>> + name_len = strlen(*extlist);
>>> + min_len = name_len < len ? name_len : len;
>>> + ret = strncmp(*extlist, name, min_len);
>>
>> How about using strcmp(*extlist, name)? It will return 0 only if the two strings
>> are the same.
>>
> Hi, Chao Yu
>
> Thanks for your reply. I was considering strcmp may have security issue.
Could you share details about the security issue of using strcmp?
Thanks,
>>> +
>>> + if (ret == 0 && name_len == len)
>>> + return 1;
>>> + extlist++;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> static void configure_extension_list(void)
>>> {
>>> const char **extlist = media_ext_lists;
>>> @@ -144,7 +164,8 @@ static void configure_extension_list(void)
>>> ue = strtok(ext_str, ",");
>>> while (ue != NULL) {
>>> name_len = strlen(ue);
>>
>> We should verify the length of extension to avoid memcpy overflow. I will send a
>> patch for fixing.
> I agree. And I think we should make sure there is a '\0' at the end of each string
> in extension_list.
>>
>>> - memcpy(sb.extension_list[i++], ue, name_len);
>>> + if (!extension_exist(ue, name_len))
>>
>> How do you think of comparing extension user defined with sb.extension_list?
>> In this way, duplication user defined can be avoided completely.
> Right. I'll send a v2 latter.
>
> thanks,
> Sheng
>>
>> Thanks,
>>
>>> + memcpy(sb.extension_list[i++], ue, name_len);
>>> ue = strtok(NULL, ",");
>>> if (i >= F2FS_MAX_EXTENSION)
>>> break;
>>>
>>
>> .
>>
>
------------------------------------------------------------------------------
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC PATCH] mkfs.f2fs: avoid dumplicate extension
2015-11-28 2:31 ` Chao Yu
@ 2015-11-28 2:45 ` Sheng Yong
0 siblings, 0 replies; 5+ messages in thread
From: Sheng Yong @ 2015-11-28 2:45 UTC (permalink / raw)
To: Chao Yu; +Cc: jaegeuk, linux-f2fs-devel
On 11/28/2015 10:31 AM, Chao Yu wrote:
> Hi Sheng Yong,
>
> On 11/28/15 8:39 AM, Sheng Yong wrote:
>>
>> On 11/27/2015 9:09 PM, Chao Yu wrote:
>>> Hi Sheng Yong,
>>>
>>> On 11/28/15 12:55 AM, Sheng Yong wrote:
>>>> Before copying user specified extension to extension_list, check if it is
>>>> already in the list.
>>>>
>>>> Signed-off-by: Sheng Yong <shengyong1@huawei.com>
>>>> ---
>>>> mkfs/f2fs_format.c | 23 ++++++++++++++++++++++-
>>>> 1 file changed, 22 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
>>>> index 176bdea..b7ea19f 100644
>>>> --- a/mkfs/f2fs_format.c
>>>> +++ b/mkfs/f2fs_format.c
>>>> @@ -118,6 +118,26 @@ const char *media_ext_lists[] = {
>>>> NULL
>>>> };
>>>>
>>>> +static int extension_exist(const char *name, const int len)
>>>
>>> bool is_extension_exist?
>>>
>>>> +{
>>>> + const char **extlist = media_ext_lists;
>>>> + int name_len, min_len;
>>>> + int ret;
>>>> +
>>>> +
>>>> + while (*extlist) {
>>>> + name_len = strlen(*extlist);
>>>> + min_len = name_len < len ? name_len : len;
>>>> + ret = strncmp(*extlist, name, min_len);
>>>
>>> How about using strcmp(*extlist, name)? It will return 0 only if the two strings
>>> are the same.
>>>
>> Hi, Chao Yu
>>
>> Thanks for your reply. I was considering strcmp may have security issue.
>
> Could you share details about the security issue of using strcmp?
I was wrong, please ignore this :(
thanks,
Sheng
>
> Thanks,
>
>>>> +
>>>> + if (ret == 0 && name_len == len)
>>>> + return 1;
>>>> + extlist++;
>>>> + }
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> static void configure_extension_list(void)
>>>> {
>>>> const char **extlist = media_ext_lists;
>>>> @@ -144,7 +164,8 @@ static void configure_extension_list(void)
>>>> ue = strtok(ext_str, ",");
>>>> while (ue != NULL) {
>>>> name_len = strlen(ue);
>>>
>>> We should verify the length of extension to avoid memcpy overflow. I will send a
>>> patch for fixing.
>> I agree. And I think we should make sure there is a '\0' at the end of each string
>> in extension_list.
>>>
>>>> - memcpy(sb.extension_list[i++], ue, name_len);
>>>> + if (!extension_exist(ue, name_len))
>>>
>>> How do you think of comparing extension user defined with sb.extension_list?
>>> In this way, duplication user defined can be avoided completely.
>> Right. I'll send a v2 latter.
>>
>> thanks,
>> Sheng
>>>
>>> Thanks,
>>>
>>>> + memcpy(sb.extension_list[i++], ue, name_len);
>>>> ue = strtok(NULL, ",");
>>>> if (i >= F2FS_MAX_EXTENSION)
>>>> break;
>>>>
>>>
>>> .
>>>
>>
>
> .
>
------------------------------------------------------------------------------
^ permalink raw reply [flat|nested] 5+ messages in thread
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2015-11-27 16:55 [RFC PATCH] mkfs.f2fs: avoid dumplicate extension Sheng Yong
2015-11-27 13:09 ` Chao Yu
2015-11-28 0:39 ` Sheng Yong
2015-11-28 2:31 ` Chao Yu
2015-11-28 2:45 ` Sheng Yong
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