* [PATCH] wifi: mwifiex: Replace strlcpy with strscpy
@ 2023-07-10 3:06 Azeem Shaikh
2023-07-12 23:55 ` Kees Cook
2023-07-27 15:52 ` Kees Cook
0 siblings, 2 replies; 7+ messages in thread
From: Azeem Shaikh @ 2023-07-10 3:06 UTC (permalink / raw)
To: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam, Xinming Hu
Cc: linux-hardening, Azeem Shaikh, linux-wireless, linux-kernel, Kalle Valo
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
Direct replacement is safe here since return value of -errno
is used to check for truncation instead of sizeof(dest).
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
drivers/net/wireless/marvell/mwifiex/main.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/main.c b/drivers/net/wireless/marvell/mwifiex/main.c
index 1cd9d20cca16..8d3c4bcf9c89 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.c
+++ b/drivers/net/wireless/marvell/mwifiex/main.c
@@ -725,9 +725,8 @@ static int mwifiex_init_hw_fw(struct mwifiex_adapter *adapter,
* manufacturing mode is enabled
*/
if (mfg_mode) {
- if (strlcpy(adapter->fw_name, MFG_FIRMWARE,
- sizeof(adapter->fw_name)) >=
- sizeof(adapter->fw_name)) {
+ if (strscpy(adapter->fw_name, MFG_FIRMWARE,
+ sizeof(adapter->fw_name)) < 0) {
pr_err("%s: fw_name too long!\n", __func__);
return -1;
}
--
2.41.0.255.g8b1d071c50-goog
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace strlcpy with strscpy
2023-07-10 3:06 [PATCH] wifi: mwifiex: Replace strlcpy with strscpy Azeem Shaikh
@ 2023-07-12 23:55 ` Kees Cook
2023-07-27 15:52 ` Kees Cook
1 sibling, 0 replies; 7+ messages in thread
From: Kees Cook @ 2023-07-12 23:55 UTC (permalink / raw)
To: Azeem Shaikh
Cc: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam,
Xinming Hu, linux-hardening, linux-wireless, linux-kernel,
Kalle Valo
On Mon, Jul 10, 2023 at 03:06:25AM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
>
> Direct replacement is safe here since return value of -errno
> is used to check for truncation instead of sizeof(dest).
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
>
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace strlcpy with strscpy
2023-07-10 3:06 [PATCH] wifi: mwifiex: Replace strlcpy with strscpy Azeem Shaikh
2023-07-12 23:55 ` Kees Cook
@ 2023-07-27 15:52 ` Kees Cook
2023-07-27 16:02 ` Kalle Valo
1 sibling, 1 reply; 7+ messages in thread
From: Kees Cook @ 2023-07-27 15:52 UTC (permalink / raw)
To: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam,
Xinming Hu, Azeem Shaikh
Cc: Kees Cook, linux-hardening, linux-wireless, linux-kernel, Kalle Valo
On Mon, 10 Jul 2023 03:06:25 +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
>
> [...]
Applied, thanks!
[1/1] wifi: mwifiex: Replace strlcpy with strscpy
https://git.kernel.org/kees/c/5469fb73e96d
Best regards,
--
Kees Cook
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace strlcpy with strscpy
2023-07-27 15:52 ` Kees Cook
@ 2023-07-27 16:02 ` Kalle Valo
2023-07-27 17:04 ` Kees Cook
0 siblings, 1 reply; 7+ messages in thread
From: Kalle Valo @ 2023-07-27 16:02 UTC (permalink / raw)
To: Kees Cook
Cc: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam,
Xinming Hu, Azeem Shaikh, linux-hardening, linux-wireless,
linux-kernel
Kees Cook <keescook@chromium.org> writes:
> On Mon, 10 Jul 2023 03:06:25 +0000, Azeem Shaikh wrote:
>> strlcpy() reads the entire source buffer first.
>> This read may exceed the destination size limit.
>> This is both inefficient and can lead to linear read
>> overflows if a source string is not NUL-terminated [1].
>> In an effort to remove strlcpy() completely [2], replace
>> strlcpy() here with strscpy().
>>
>> [...]
>
> Applied, thanks!
>
> [1/1] wifi: mwifiex: Replace strlcpy with strscpy
> https://git.kernel.org/kees/c/5469fb73e96d
And the same question here, why are you taking wifi patches without
acks? And this already fixed differently in wireless-next so our trees
conflict now:
https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git/commit/?id=caf9ead2c7d06fd7aa4cb48bd569ad61db9a0b4a
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace strlcpy with strscpy
2023-07-27 16:02 ` Kalle Valo
@ 2023-07-27 17:04 ` Kees Cook
2023-07-27 17:30 ` Brian Norris
0 siblings, 1 reply; 7+ messages in thread
From: Kees Cook @ 2023-07-27 17:04 UTC (permalink / raw)
To: Kalle Valo
Cc: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam,
Xinming Hu, Azeem Shaikh, linux-hardening, linux-wireless,
linux-kernel
On Thu, Jul 27, 2023 at 07:02:31PM +0300, Kalle Valo wrote:
> Kees Cook <keescook@chromium.org> writes:
>
> > On Mon, 10 Jul 2023 03:06:25 +0000, Azeem Shaikh wrote:
> >> strlcpy() reads the entire source buffer first.
> >> This read may exceed the destination size limit.
> >> This is both inefficient and can lead to linear read
> >> overflows if a source string is not NUL-terminated [1].
> >> In an effort to remove strlcpy() completely [2], replace
> >> strlcpy() here with strscpy().
> >>
> >> [...]
> >
> > Applied, thanks!
> >
> > [1/1] wifi: mwifiex: Replace strlcpy with strscpy
> > https://git.kernel.org/kees/c/5469fb73e96d
>
> And the same question here, why are you taking wifi patches without
> acks? And this already fixed differently in wireless-next so our trees
> conflict now:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git/commit/?id=caf9ead2c7d06fd7aa4cb48bd569ad61db9a0b4a
Thanks for pointing that out! I saw no feedback on Azeem's patch, so it
looked like it was being ignored.
For the patch you linked to -- it's okay to have lost the overflow
detection and warning?
Regardless, I will drop this from my tree.
-Kees
--
Kees Cook
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace strlcpy with strscpy
2023-07-27 17:04 ` Kees Cook
@ 2023-07-27 17:30 ` Brian Norris
2023-07-27 18:04 ` Kees Cook
0 siblings, 1 reply; 7+ messages in thread
From: Brian Norris @ 2023-07-27 17:30 UTC (permalink / raw)
To: Kees Cook
Cc: Kalle Valo, Amitkumar Karwar, Ganapathi Bhat,
Sharvari Harisangam, Xinming Hu, Azeem Shaikh, linux-hardening,
linux-wireless, linux-kernel
On Thu, Jul 27, 2023 at 10:04 AM Kees Cook <keescook@chromium.org> wrote:
>
> On Thu, Jul 27, 2023 at 07:02:31PM +0300, Kalle Valo wrote:
> > https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git/commit/?id=caf9ead2c7d06fd7aa4cb48bd569ad61db9a0b4a
>
> For the patch you linked to -- it's okay to have lost the overflow
> detection and warning?
It's a fixed constant string being copied into a larger fixed array.
It really doesn't matter functionality-wise. At best, the error check
would be useful for human readers or automated tools. So I didn't
bother complaining one way or another, as it took enough tries for the
submitter to get things right in the first place.
Brian
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace strlcpy with strscpy
2023-07-27 17:30 ` Brian Norris
@ 2023-07-27 18:04 ` Kees Cook
0 siblings, 0 replies; 7+ messages in thread
From: Kees Cook @ 2023-07-27 18:04 UTC (permalink / raw)
To: Brian Norris
Cc: Kalle Valo, Amitkumar Karwar, Ganapathi Bhat,
Sharvari Harisangam, Xinming Hu, Azeem Shaikh, linux-hardening,
linux-wireless, linux-kernel
On Thu, Jul 27, 2023 at 10:30:29AM -0700, Brian Norris wrote:
> On Thu, Jul 27, 2023 at 10:04 AM Kees Cook <keescook@chromium.org> wrote:
> >
> > On Thu, Jul 27, 2023 at 07:02:31PM +0300, Kalle Valo wrote:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git/commit/?id=caf9ead2c7d06fd7aa4cb48bd569ad61db9a0b4a
> >
> > For the patch you linked to -- it's okay to have lost the overflow
> > detection and warning?
>
> It's a fixed constant string being copied into a larger fixed array.
> It really doesn't matter functionality-wise. At best, the error check
> would be useful for human readers or automated tools. So I didn't
> bother complaining one way or another, as it took enough tries for the
> submitter to get things right in the first place.
Gotcha. Thanks!
--
Kees Cook
^ permalink raw reply [flat|nested] 7+ messages in thread
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2023-07-10 3:06 [PATCH] wifi: mwifiex: Replace strlcpy with strscpy Azeem Shaikh
2023-07-12 23:55 ` Kees Cook
2023-07-27 15:52 ` Kees Cook
2023-07-27 16:02 ` Kalle Valo
2023-07-27 17:04 ` Kees Cook
2023-07-27 17:30 ` Brian Norris
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