To work around a misbehavior of the compiler's ability to see into
composite flexible array structs (as detailed in the coming memcpy()
hardening series[1]), split the memcpy() of the header and the payload
so no false positive run-time overflow warning will be generated.
[1] https://lore.kernel.org/linux-hardening/[email protected]/
Cc: Alexandra Winter <[email protected]>
Cc: Wenjia Zhang <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/s390/net/qeth_l2_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 2d4436cbcb47..0ce635b7b472 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -1530,8 +1530,8 @@ static void qeth_addr_change_event(struct qeth_card *card,
else
INIT_DELAYED_WORK(&data->dwork, qeth_l2_dev2br_worker);
data->card = card;
- memcpy(&data->ac_event, hostevs,
- sizeof(struct qeth_ipacmd_addr_change) + extrasize);
+ data->ac_event = *hostevs;
+ memcpy(data->ac_event.entry, hostevs->entry, extrasize);
queue_delayed_work(card->event_wq, &data->dwork, 0);
}
--
2.34.1
On Mon, Sep 26, 2022 at 05:39:53PM -0700, Kees Cook wrote:
> To work around a misbehavior of the compiler's ability to see into
> composite flexible array structs (as detailed in the coming memcpy()
> hardening series[1]), split the memcpy() of the header and the payload
> so no false positive run-time overflow warning will be generated.
>
> [1] https://lore.kernel.org/linux-hardening/[email protected]/
>
> Cc: Alexandra Winter <[email protected]>
> Cc: Wenjia Zhang <[email protected]>
> Cc: Heiko Carstens <[email protected]>
> Cc: Vasily Gorbik <[email protected]>
> Cc: Alexander Gordeev <[email protected]>
> Cc: Christian Borntraeger <[email protected]>
> Cc: Sven Schnelle <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Thanks!
--
Gustavo
> ---
> drivers/s390/net/qeth_l2_main.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
> index 2d4436cbcb47..0ce635b7b472 100644
> --- a/drivers/s390/net/qeth_l2_main.c
> +++ b/drivers/s390/net/qeth_l2_main.c
> @@ -1530,8 +1530,8 @@ static void qeth_addr_change_event(struct qeth_card *card,
> else
> INIT_DELAYED_WORK(&data->dwork, qeth_l2_dev2br_worker);
> data->card = card;
> - memcpy(&data->ac_event, hostevs,
> - sizeof(struct qeth_ipacmd_addr_change) + extrasize);
> + data->ac_event = *hostevs;
> + memcpy(data->ac_event.entry, hostevs->entry, extrasize);
> queue_delayed_work(card->event_wq, &data->dwork, 0);
> }
>
> --
> 2.34.1
>
On 27.09.22 03:16, Gustavo A. R. Silva wrote:
> On Mon, Sep 26, 2022 at 05:39:53PM -0700, Kees Cook wrote:
>> To work around a misbehavior of the compiler's ability to see into
>> composite flexible array structs (as detailed in the coming memcpy()
>> hardening series[1]), split the memcpy() of the header and the payload
>> so no false positive run-time overflow warning will be generated.
>>
>> [1] https://lore.kernel.org/linux-hardening/[email protected]/
>>
>> Cc: Alexandra Winter <[email protected]>
>> Cc: Wenjia Zhang <[email protected]>
>> Cc: Heiko Carstens <[email protected]>
>> Cc: Vasily Gorbik <[email protected]>
>> Cc: Alexander Gordeev <[email protected]>
>> Cc: Christian Borntraeger <[email protected]>
>> Cc: Sven Schnelle <[email protected]>
>> Cc: [email protected]
>> Cc: [email protected]
>> Signed-off-by: Kees Cook <[email protected]>
>
> Reviewed-by: Gustavo A. R. Silva <[email protected]>
>
> Thanks!
> --
> Gustavo
>
Reviewed-by: Alexandra Winter <[email protected]>
Thank you
Alexandra
>> ---
>> drivers/s390/net/qeth_l2_main.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
>> index 2d4436cbcb47..0ce635b7b472 100644
>> --- a/drivers/s390/net/qeth_l2_main.c
>> +++ b/drivers/s390/net/qeth_l2_main.c
>> @@ -1530,8 +1530,8 @@ static void qeth_addr_change_event(struct qeth_card *card,
>> else
>> INIT_DELAYED_WORK(&data->dwork, qeth_l2_dev2br_worker);
>> data->card = card;
>> - memcpy(&data->ac_event, hostevs,
>> - sizeof(struct qeth_ipacmd_addr_change) + extrasize);
>> + data->ac_event = *hostevs;
>> + memcpy(data->ac_event.entry, hostevs->entry, extrasize);
>> queue_delayed_work(card->event_wq, &data->dwork, 0);
>> }
>>
>> --
>> 2.34.1
>>
Hello:
This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <[email protected]>:
On Mon, 26 Sep 2022 17:39:53 -0700 you wrote:
> To work around a misbehavior of the compiler's ability to see into
> composite flexible array structs (as detailed in the coming memcpy()
> hardening series[1]), split the memcpy() of the header and the payload
> so no false positive run-time overflow warning will be generated.
>
> [1] https://lore.kernel.org/linux-hardening/[email protected]/
>
> [...]
Here is the summary with links:
- s390/qeth: Split memcpy() of struct qeth_ipacmd_addr_change flexible array
https://git.kernel.org/netdev/net-next/c/8f1e1658d365
You are awesome, thank you!
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