From: Arnd Bergmann <[email protected]>
clang points out a potential issue with integer overflow when
the iwl_dev_info_table[] array is empty:
drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion]
for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
This is still harmless, as the loop correctly terminates, but adding
an extra range check makes that obvious to both readers and to the
compiler.
Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
Reported-by: kernel test robot <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
---
Changes in v2:
- replace int cast with a range check
---
drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
index c574f041f096..fcda7603024b 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
@@ -1341,6 +1341,9 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device,
{
int i;
+ if (ARRAY_SIZE(iwl_dev_info_table) == 0)
+ return NULL;
+
for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i];
--
2.29.2
On Thu, 2021-11-11 at 08:31 +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <[email protected]>
>
> clang points out a potential issue with integer overflow when
> the iwl_dev_info_table[] array is empty:
>
> drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion]
> for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
> ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
>
> This is still harmless, as the loop correctly terminates, but adding
> an extra range check makes that obvious to both readers and to the
> compiler.
>
> Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> Reported-by: kernel test robot <[email protected]>
> Cc: Nick Desaulniers <[email protected]>
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> Changes in v2:
> - replace int cast with a range check
> ---
> drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> index c574f041f096..fcda7603024b 100644
> --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> @@ -1341,6 +1341,9 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device,
> {
> int i;
>
> + if (ARRAY_SIZE(iwl_dev_info_table) == 0)
> + return NULL;
> +
> for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
> const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i];
This looks good now.
Acked-by: Luca Coelho <[email protected]>
Kalle, I'll assign it to you so you can take it to wireless-drivers
when it opens again.
Thanks!
--
Cheers,
Luca.
On Thu, Nov 11, 2021 at 8:31 AM Arnd Bergmann <[email protected]> wrote:
>
> From: Arnd Bergmann <[email protected]>
>
> clang points out a potential issue with integer overflow when
> the iwl_dev_info_table[] array is empty:
>
> drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion]
> for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
> ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
>
> This is still harmless, as the loop correctly terminates, but adding
> an extra range check makes that obvious to both readers and to the
> compiler.
>
> Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> Reported-by: kernel test robot <[email protected]>
> Cc: Nick Desaulniers <[email protected]>
> Signed-off-by: Arnd Bergmann <[email protected]>
Something went wrong on my end: I thought this was a clang warning and
that I had
fixed it because it didn't come back with my v2 patch. However I now see it in
my gcc-11 test builds, so I assume this was a gcc warning all along, and that
my patch does nothing. Please disregard it if you have not already applied it.
Arnd
Arnd Bergmann <[email protected]> wrote:
> From: Arnd Bergmann <[email protected]>
>
> clang points out a potential issue with integer overflow when
> the iwl_dev_info_table[] array is empty:
>
> drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion]
> for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
> ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
>
> This is still harmless, as the loop correctly terminates, but adding
> an extra range check makes that obvious to both readers and to the
> compiler.
>
> Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> Reported-by: kernel test robot <[email protected]>
> Cc: Nick Desaulniers <[email protected]>
> Signed-off-by: Arnd Bergmann <[email protected]>
> Acked-by: Luca Coelho <[email protected]>
Dropping v2 and taking v3 instead.
Patch set to Changes Requested.
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches