* [PATCH] staging: rtl8192e: prefer strscpy over strncpy
@ 2023-08-05 7:51 Michael Straube
2023-08-09 12:21 ` Greg KH
0 siblings, 1 reply; 6+ messages in thread
From: Michael Straube @ 2023-08-05 7:51 UTC (permalink / raw)
To: gregkh; +Cc: philipp.g.hortmann, linux-staging, linux-kernel, Michael Straube
Replace strncpy with strscpy in two places where the destination buffer
should be NUL-terminated. Found by checkpatch.
WARNING: Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90
Signed-off-by: Michael Straube <straube.linux@gmail.com>
---
drivers/staging/rtl8192e/rtllib_softmac.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/rtl8192e/rtllib_softmac.c b/drivers/staging/rtl8192e/rtllib_softmac.c
index 0e52b207942d..bd19d6a2ce41 100644
--- a/drivers/staging/rtl8192e/rtllib_softmac.c
+++ b/drivers/staging/rtl8192e/rtllib_softmac.c
@@ -1564,7 +1564,7 @@ inline void rtllib_softmac_new_net(struct rtllib_device *ieee,
(!strncmp(ieee->current_network.ssid,
net->hidden_ssid, net->hidden_ssid_len));
if (net->hidden_ssid_len > 0) {
- strncpy(net->ssid, net->hidden_ssid,
+ strscpy(net->ssid, net->hidden_ssid,
net->hidden_ssid_len);
net->ssid_len = net->hidden_ssid_len;
ssidbroad = 1;
@@ -2431,7 +2431,7 @@ static void rtllib_start_master_bss(struct rtllib_device *ieee)
ieee->assoc_id = 1;
if (ieee->current_network.ssid_len == 0) {
- strncpy(ieee->current_network.ssid,
+ strscpy(ieee->current_network.ssid,
RTLLIB_DEFAULT_TX_ESSID,
IW_ESSID_MAX_SIZE);
--
2.41.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] staging: rtl8192e: prefer strscpy over strncpy
2023-08-05 7:51 [PATCH] staging: rtl8192e: prefer strscpy over strncpy Michael Straube
@ 2023-08-09 12:21 ` Greg KH
2023-08-09 18:02 ` Michael Straube
0 siblings, 1 reply; 6+ messages in thread
From: Greg KH @ 2023-08-09 12:21 UTC (permalink / raw)
To: Michael Straube; +Cc: philipp.g.hortmann, linux-staging, linux-kernel
On Sat, Aug 05, 2023 at 09:51:14AM +0200, Michael Straube wrote:
> Replace strncpy with strscpy in two places where the destination buffer
> should be NUL-terminated. Found by checkpatch.
>
> WARNING: Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90
If a global search/replace could be done, it would have happend a long
time ago.
How was this tested? The functions work differently, are you sure there
is no change in functionality here?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] staging: rtl8192e: prefer strscpy over strncpy
2023-08-09 12:21 ` Greg KH
@ 2023-08-09 18:02 ` Michael Straube
2023-08-10 5:01 ` Dan Carpenter
0 siblings, 1 reply; 6+ messages in thread
From: Michael Straube @ 2023-08-09 18:02 UTC (permalink / raw)
To: Greg KH; +Cc: philipp.g.hortmann, linux-staging, linux-kernel
On 8/9/23 14:21, Greg KH wrote:
> On Sat, Aug 05, 2023 at 09:51:14AM +0200, Michael Straube wrote:
>> Replace strncpy with strscpy in two places where the destination buffer
>> should be NUL-terminated. Found by checkpatch.
>>
>> WARNING: Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90
>
> If a global search/replace could be done, it would have happend a long
> time ago.
>
> How was this tested? The functions work differently, are you sure there
> is no change in functionality here?
>
It was only compile tested. To me it looked as it does not change
functionality, but looking a bit deeper at it I'm not sure anymore.
So, we should leave it as is.
thank you
Michael
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] staging: rtl8192e: prefer strscpy over strncpy
2023-08-09 18:02 ` Michael Straube
@ 2023-08-10 5:01 ` Dan Carpenter
2023-08-25 5:13 ` Michael Straube
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2023-08-10 5:01 UTC (permalink / raw)
To: Michael Straube; +Cc: Greg KH, philipp.g.hortmann, linux-staging, linux-kernel
On Wed, Aug 09, 2023 at 08:02:05PM +0200, Michael Straube wrote:
> On 8/9/23 14:21, Greg KH wrote:
> > On Sat, Aug 05, 2023 at 09:51:14AM +0200, Michael Straube wrote:
> > > Replace strncpy with strscpy in two places where the destination buffer
> > > should be NUL-terminated. Found by checkpatch.
> > >
> > > WARNING: Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90
> >
> > If a global search/replace could be done, it would have happend a long
> > time ago.
> >
> > How was this tested? The functions work differently, are you sure there
> > is no change in functionality here?
> >
>
> It was only compile tested. To me it looked as it does not change
> functionality, but looking a bit deeper at it I'm not sure anymore.
> So, we should leave it as is.
So there are three main differences between strncpy() and strcpy().
1) The return.
2) strncpy() will always write net->hidden_ssid_len bytes. If the
string to copy is smaller than net->hidden_ssid_len bytes it will
fill the rest with zeroes. This can be important for preventing
information leaks.
3) strscpy() will always add a NUL terminator where strncpy() just
truncates a too long string without adding a terminator.
We want #3. We don't care about #1. The only thing to check is #2.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] staging: rtl8192e: prefer strscpy over strncpy
2023-08-10 5:01 ` Dan Carpenter
@ 2023-08-25 5:13 ` Michael Straube
2023-09-05 9:23 ` Dan Carpenter
0 siblings, 1 reply; 6+ messages in thread
From: Michael Straube @ 2023-08-25 5:13 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Greg KH, philipp.g.hortmann, linux-staging, linux-kernel
On 8/10/23 07:01, Dan Carpenter wrote:
> On Wed, Aug 09, 2023 at 08:02:05PM +0200, Michael Straube wrote:
>> On 8/9/23 14:21, Greg KH wrote:
>>> On Sat, Aug 05, 2023 at 09:51:14AM +0200, Michael Straube wrote:
>>>> Replace strncpy with strscpy in two places where the destination buffer
>>>> should be NUL-terminated. Found by checkpatch.
>>>>
>>>> WARNING: Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90
>>>
>>> If a global search/replace could be done, it would have happend a long
>>> time ago.
>>>
>>> How was this tested? The functions work differently, are you sure there
>>> is no change in functionality here?
>>>
>>
>> It was only compile tested. To me it looked as it does not change
>> functionality, but looking a bit deeper at it I'm not sure anymore.
>> So, we should leave it as is.
>
> So there are three main differences between strncpy() and strcpy().
>
> 1) The return.
> 2) strncpy() will always write net->hidden_ssid_len bytes. If the
> string to copy is smaller than net->hidden_ssid_len bytes it will
> fill the rest with zeroes. This can be important for preventing
> information leaks.
> 3) strscpy() will always add a NUL terminator where strncpy() just
> truncates a too long string without adding a terminator.
>
> We want #3. We don't care about #1. The only thing to check is #2.
>
> regards,
> dan carpenter
>
Thank you Dan,
so in this case we should/could replace strncpy with strscpy_pad,
correct?
regards,
Michael
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] staging: rtl8192e: prefer strscpy over strncpy
2023-08-25 5:13 ` Michael Straube
@ 2023-09-05 9:23 ` Dan Carpenter
0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2023-09-05 9:23 UTC (permalink / raw)
To: Michael Straube; +Cc: Greg KH, philipp.g.hortmann, linux-staging, linux-kernel
On Fri, Aug 25, 2023 at 07:13:42AM +0200, Michael Straube wrote:
> On 8/10/23 07:01, Dan Carpenter wrote:
> > On Wed, Aug 09, 2023 at 08:02:05PM +0200, Michael Straube wrote:
> > > On 8/9/23 14:21, Greg KH wrote:
> > > > On Sat, Aug 05, 2023 at 09:51:14AM +0200, Michael Straube wrote:
> > > > > Replace strncpy with strscpy in two places where the destination buffer
> > > > > should be NUL-terminated. Found by checkpatch.
> > > > >
> > > > > WARNING: Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90
> > > >
> > > > If a global search/replace could be done, it would have happend a long
> > > > time ago.
> > > >
> > > > How was this tested? The functions work differently, are you sure there
> > > > is no change in functionality here?
> > > >
> > >
> > > It was only compile tested. To me it looked as it does not change
> > > functionality, but looking a bit deeper at it I'm not sure anymore.
> > > So, we should leave it as is.
> >
> > So there are three main differences between strncpy() and strcpy().
> >
> > 1) The return.
> > 2) strncpy() will always write net->hidden_ssid_len bytes. If the
> > string to copy is smaller than net->hidden_ssid_len bytes it will
> > fill the rest with zeroes. This can be important for preventing
> > information leaks.
> > 3) strscpy() will always add a NUL terminator where strncpy() just
> > truncates a too long string without adding a terminator.
> >
> > We want #3. We don't care about #1. The only thing to check is #2.
> >
> > regards,
> > dan carpenter
> >
>
> Thank you Dan,
>
> so in this case we should/could replace strncpy with strscpy_pad,
> correct?
I'm pretty sure that strscpy() was correct. It requires some analysis
in how this is initialized and/or used.
Don't just automatically use strscpy_pad() to try avoid doing the
analysis. ;)
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
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2023-08-05 7:51 [PATCH] staging: rtl8192e: prefer strscpy over strncpy Michael Straube
2023-08-09 12:21 ` Greg KH
2023-08-09 18:02 ` Michael Straube
2023-08-10 5:01 ` Dan Carpenter
2023-08-25 5:13 ` Michael Straube
2023-09-05 9:23 ` Dan Carpenter
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