| Message ID | 20230920-strncpy-drivers-i2c-busses-i2c-powermac-c-v1-1-0a3e9a107f8a@google.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 65917718fb8bc2c94df3d52c054116c0e2e640cc |
| Headers | show |
| Series | i2c: replace deprecated strncpy | expand |
On Wed, Sep 20, 2023 at 11:07:35AM +0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings [1]. > > We should prefer more robust and less ambiguous string interfaces. > > `info.type` is expected to be NUL-terminated judging by its use in > `i2c_new_client_device()` wherein it is used to populate `client->name`: > | strscpy(client->name, info->type, sizeof(client->name)); > > NUL-padding is not required and even if it was, `client` is already > zero-initialized. > > Considering the two points from above, a suitable replacement is > `strscpy` [2] due to the fact that it guarantees NUL-termination on the > destination buffer without unnecessarily NUL-padding. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Justin Stitt <justinstitt@google.com> Looks like a straight replacement. Thanks! Reviewed-by: Kees Cook <keescook@chromium.org>
On Wed, Sep 20, 2023 at 11:07:35AM +0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings [1]. > > We should prefer more robust and less ambiguous string interfaces. > > `info.type` is expected to be NUL-terminated judging by its use in > `i2c_new_client_device()` wherein it is used to populate `client->name`: > | strscpy(client->name, info->type, sizeof(client->name)); > > NUL-padding is not required and even if it was, `client` is already > zero-initialized. > > Considering the two points from above, a suitable replacement is > `strscpy` [2] due to the fact that it guarantees NUL-termination on the > destination buffer without unnecessarily NUL-padding. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Justin Stitt <justinstitt@google.com> Added "powermac: " to $subject and applied to for-next, thanks!
diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c index 4996a628fdae..8e57ebe595be 100644 --- a/drivers/i2c/busses/i2c-powermac.c +++ b/drivers/i2c/busses/i2c-powermac.c @@ -231,7 +231,7 @@ static void i2c_powermac_create_one(struct i2c_adapter *adap, struct i2c_board_info info = {}; struct i2c_client *newdev; - strncpy(info.type, type, sizeof(info.type)); + strscpy(info.type, type, sizeof(info.type)); info.addr = addr; newdev = i2c_new_client_device(adap, &info); if (IS_ERR(newdev))
`strncpy` is deprecated for use on NUL-terminated destination strings [1]. We should prefer more robust and less ambiguous string interfaces. `info.type` is expected to be NUL-terminated judging by its use in `i2c_new_client_device()` wherein it is used to populate `client->name`: | strscpy(client->name, info->type, sizeof(client->name)); NUL-padding is not required and even if it was, `client` is already zero-initialized. Considering the two points from above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> --- drivers/i2c/busses/i2c-powermac.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: 2cf0f715623872823a72e451243bbf555d10d032 change-id: 20230920-strncpy-drivers-i2c-busses-i2c-powermac-c-a95017b69711 Best regards, -- Justin Stitt <justinstitt@google.com>