Kees Cook <[email protected]> wrote:
> In an effort to separate intentional arithmetic wrap-around from
> unexpected wrap-around, we need to refactor places that depend on this
> kind of math. One of the most common code patterns of this is:
>
> VAR + value < VAR
>
> Notably, this is considered "undefined behavior" for signed and pointer
> types, which the kernel works around by using the -fno-strict-overflow
> option in the build[1] (which used to just be -fwrapv). Regardless, we
> want to get the kernel source to the position where we can meaningfully
> instrument arithmetic wrap-around conditions and catch them when they
> are unexpected, regardless of whether they are signed[2], unsigned[3],
> or pointer[4] types.
>
> Refactor open-coded wrap-around addition test to use add_would_overflow().
> This paves the way to enabling the wrap-around sanitizers in the future.
>
> Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f18536594 [1]
> Link: https://github.com/KSPP/linux/issues/26 [2]
> Link: https://github.com/KSPP/linux/issues/27 [3]
> Link: https://github.com/KSPP/linux/issues/344 [4]
> Cc: Kalle Valo <[email protected]>
> Cc: Johannes Berg <[email protected]>
> Cc: Max Chen <[email protected]>
> Cc: Yang Shen <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> Acked-by: Kalle Valo <[email protected]>
If you can edit before commit please add "wifi:" prefix to the wireless patches:
ERROR: 'wifi:' prefix missing: '[PATCH 41/82] wil6210: Refactor intentional wrap-around test'
ERROR: 'wifi:' prefix missing: '[PATCH 62/82] mwifiex: pcie: Refactor intentional wrap-around test'
2 patches set to Not Applicable.
13526631 [41/82] wil6210: Refactor intentional wrap-around test
13526632 [62/82] mwifiex: pcie: Refactor intentional wrap-around test
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
On Tue, Jan 23, 2024 at 11:50:34AM +0000, Kalle Valo wrote:
> Kees Cook <[email protected]> wrote:
>
> > In an effort to separate intentional arithmetic wrap-around from
> > unexpected wrap-around, we need to refactor places that depend on this
> > kind of math. One of the most common code patterns of this is:
> >
> > VAR + value < VAR
> >
> > Notably, this is considered "undefined behavior" for signed and pointer
> > types, which the kernel works around by using the -fno-strict-overflow
> > option in the build[1] (which used to just be -fwrapv). Regardless, we
> > want to get the kernel source to the position where we can meaningfully
> > instrument arithmetic wrap-around conditions and catch them when they
> > are unexpected, regardless of whether they are signed[2], unsigned[3],
> > or pointer[4] types.
> >
> > Refactor open-coded wrap-around addition test to use add_would_overflow().
> > This paves the way to enabling the wrap-around sanitizers in the future.
> >
> > Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f18536594 [1]
> > Link: https://github.com/KSPP/linux/issues/26 [2]
> > Link: https://github.com/KSPP/linux/issues/27 [3]
> > Link: https://github.com/KSPP/linux/issues/344 [4]
> > Cc: Kalle Valo <[email protected]>
> > Cc: Johannes Berg <[email protected]>
> > Cc: Max Chen <[email protected]>
> > Cc: Yang Shen <[email protected]>
> > Cc: [email protected]
> > Signed-off-by: Kees Cook <[email protected]>
> > Acked-by: Kalle Valo <[email protected]>
>
> If you can edit before commit please add "wifi:" prefix to the wireless patches:
>
> ERROR: 'wifi:' prefix missing: '[PATCH 41/82] wil6210: Refactor intentional wrap-around test'
> ERROR: 'wifi:' prefix missing: '[PATCH 62/82] mwifiex: pcie: Refactor intentional wrap-around test'
Ah yes, thank you! I will adjust them.
-Kees
>
> 2 patches set to Not Applicable.
>
> 13526631 [41/82] wil6210: Refactor intentional wrap-around test
> 13526632 [62/82] mwifiex: pcie: Refactor intentional wrap-around test
>
> --
> https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
>
--
Kees Cook