[v2] wifi: ipw2x00: refactor to use kstrtoul
Commit Message
The current implementation seems to reinvent what `kstrtoul` already does
in terms of functionality and error handling. Remove uses of `simple_strtoul()`
in favor of `kstrtoul()`.
There is the following note at `lib/vsprintf.c:simple_strtoull()` which
further backs this change:
| * This function has caveats. Please use kstrtoull (or kstrtoul) instead.
And here, simple_str* are explicitly deprecated [3].
This patch also removes an instance of the deprecated `strncpy` which helps [2].
Link: https://lore.kernel.org/all/202308011602.3CC1C0244C@keescook/ [1]
Link: https://github.com/KSPP/linux/issues/90 [2]
Link: https://docs.kernel.org/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull [3]
Cc: linux-hardening@vger.kernel.org
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Link: https://lore.kernel.org/all/20230801-drivers-net-wireless-intel-ipw2x00-v1-1-ffd185c91292@google.com/
---
Changes in v2:
- Create unsigned long and pass reference to kstrtoul (thanks Kees)
- Link to v1: https://lore.kernel.org/r/20230802-wifi-ipw2x00-refactor-v1-1-6047659410d4@google.com
---
drivers/net/wireless/intel/ipw2x00/ipw2200.c | 39 +++++++++-------------------
1 file changed, 12 insertions(+), 27 deletions(-)
---
base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
change-id: 20230801-wifi-ipw2x00-refactor-fa6deb6c67ea
Best regards,
--
Justin Stitt <justinstitt@google.com>
Comments
Justin Stitt <justinstitt@google.com> wrote:
> The current implementation seems to reinvent what `kstrtoul` already does
> in terms of functionality and error handling. Remove uses of `simple_strtoul()`
> in favor of `kstrtoul()`.
>
> There is the following note at `lib/vsprintf.c:simple_strtoull()` which
> further backs this change:
> | * This function has caveats. Please use kstrtoull (or kstrtoul) instead.
>
> And here, simple_str* are explicitly deprecated [3].
>
> This patch also removes an instance of the deprecated `strncpy` which helps [2].
>
> Link: https://lore.kernel.org/all/202308011602.3CC1C0244C@keescook/ [1]
> Link: https://github.com/KSPP/linux/issues/90 [2]
> Link: https://docs.kernel.org/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull [3]
> Cc: linux-hardening@vger.kernel.org
> Suggested-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
I assume this is just compile tested? In that case it's always good to add
"Compile tested only." to the commit log. But I can add that this time.
On Wed, Aug 02, 2023 at 01:23:06AM +0000, Justin Stitt wrote:
> The current implementation seems to reinvent what `kstrtoul` already does
> in terms of functionality and error handling. Remove uses of `simple_strtoul()`
> in favor of `kstrtoul()`.
>
> There is the following note at `lib/vsprintf.c:simple_strtoull()` which
> further backs this change:
> | * This function has caveats. Please use kstrtoull (or kstrtoul) instead.
>
> And here, simple_str* are explicitly deprecated [3].
>
> This patch also removes an instance of the deprecated `strncpy` which helps [2].
>
> Link: https://lore.kernel.org/all/202308011602.3CC1C0244C@keescook/ [1]
> Link: https://github.com/KSPP/linux/issues/90 [2]
> Link: https://docs.kernel.org/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull [3]
> Cc: linux-hardening@vger.kernel.org
> Suggested-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
This looks correct to me. I would be curious to hear back from the intel
folks if the interface continues to work correctly with real hardware.
Reviewed-by: Kees Cook <keescook@chromium.org>
Kees Cook <keescook@chromium.org> writes:
> On Wed, Aug 02, 2023 at 01:23:06AM +0000, Justin Stitt wrote:
>> The current implementation seems to reinvent what `kstrtoul` already does
>> in terms of functionality and error handling. Remove uses of `simple_strtoul()`
>> in favor of `kstrtoul()`.
>>
>> There is the following note at `lib/vsprintf.c:simple_strtoull()` which
>> further backs this change:
>> | * This function has caveats. Please use kstrtoull (or kstrtoul) instead.
>>
>> And here, simple_str* are explicitly deprecated [3].
>>
>> This patch also removes an instance of the deprecated `strncpy` which helps [2].
>>
>> Link: https://lore.kernel.org/all/202308011602.3CC1C0244C@keescook/ [1]
>> Link: https://github.com/KSPP/linux/issues/90 [2]
>> Link:
>> https://docs.kernel.org/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull
>> [3]
>> Cc: linux-hardening@vger.kernel.org
>> Suggested-by: Kees Cook <keescook@chromium.org>
>> Signed-off-by: Justin Stitt <justinstitt@google.com>
>
> This looks correct to me. I would be curious to hear back from the intel
> folks if the interface continues to work correctly with real hardware.
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
This is ancient hardware, not sure if anyone even have a working setup.
And even if they would have one I doubt anyone uses this sysfs interface
for anything.
Justin Stitt <justinstitt@google.com> wrote:
> The current implementation seems to reinvent what `kstrtoul` already does
> in terms of functionality and error handling. Remove uses of `simple_strtoul()`
> in favor of `kstrtoul()`.
>
> There is the following note at `lib/vsprintf.c:simple_strtoull()` which
> further backs this change:
> | * This function has caveats. Please use kstrtoull (or kstrtoul) instead.
>
> And here, simple_str* are explicitly deprecated [3].
>
> This patch also removes an instance of the deprecated `strncpy` which helps [2].
>
> Compile tested only.
>
> Link: https://lore.kernel.org/all/202308011602.3CC1C0244C@keescook/ [1]
> Link: https://github.com/KSPP/linux/issues/90 [2]
> Link: https://docs.kernel.org/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull [3]
> Cc: linux-hardening@vger.kernel.org
> Suggested-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
Patch applied to wireless-next.git, thanks.
876777494634 wifi: ipw2x00: refactor to use kstrtoul
@@ -1176,23 +1176,20 @@ static ssize_t debug_level_show(struct device_driver *d, char *buf)
static ssize_t debug_level_store(struct device_driver *d, const char *buf,
size_t count)
{
- char *p = (char *)buf;
- u32 val;
+ unsigned long val;
- if (p[1] == 'x' || p[1] == 'X' || p[0] == 'x' || p[0] == 'X') {
- p++;
- if (p[0] == 'x' || p[0] == 'X')
- p++;
- val = simple_strtoul(p, &p, 16);
- } else
- val = simple_strtoul(p, &p, 10);
- if (p == buf)
+ int result = kstrtoul(buf, 0, &val);
+
+ if (result == -EINVAL)
printk(KERN_INFO DRV_NAME
": %s is not in hex or decimal form.\n", buf);
+ else if (result == -ERANGE)
+ printk(KERN_INFO DRV_NAME
+ ": %s has overflowed.\n", buf);
else
ipw_debug_level = val;
- return strnlen(buf, count);
+ return count;
}
static DRIVER_ATTR_RW(debug_level);
@@ -1461,25 +1458,13 @@ static ssize_t scan_age_store(struct device *d, struct device_attribute *attr,
{
struct ipw_priv *priv = dev_get_drvdata(d);
struct net_device *dev = priv->net_dev;
- char buffer[] = "00000000";
- unsigned long len =
- (sizeof(buffer) - 1) > count ? count : sizeof(buffer) - 1;
- unsigned long val;
- char *p = buffer;
IPW_DEBUG_INFO("enter\n");
- strncpy(buffer, buf, len);
- buffer[len] = 0;
+ unsigned long val;
+ int result = kstrtoul(buf, 0, &val);
- if (p[1] == 'x' || p[1] == 'X' || p[0] == 'x' || p[0] == 'X') {
- p++;
- if (p[0] == 'x' || p[0] == 'X')
- p++;
- val = simple_strtoul(p, &p, 16);
- } else
- val = simple_strtoul(p, &p, 10);
- if (p == buffer) {
+ if (result == -EINVAL || result == -ERANGE) {
IPW_DEBUG_INFO("%s: user supplied invalid value.\n", dev->name);
} else {
priv->ieee->scan_age = val;
@@ -1487,7 +1472,7 @@ static ssize_t scan_age_store(struct device *d, struct device_attribute *attr,
}
IPW_DEBUG_INFO("exit\n");
- return len;
+ return count;
}
static DEVICE_ATTR_RW(scan_age);