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 <[email protected]>
---
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
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 <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook
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
Kees Cook <[email protected]> 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
On Thu, Jul 27, 2023 at 07:02:31PM +0300, Kalle Valo wrote:
> Kees Cook <[email protected]> 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