Function ssb_get_devtypedata(dev) may return null (next call
B43legacy_WARN_ON(!wl) is used for error handling, including null-value).
Therefore, a check is added before calling b43legacy_wireless_exit(),
where the argument containing this value is expected to be dereferenced.
Found by Linux Verification Center (linuxtesting.org) with SVACE
Fixes: 75388acd0cd8 ("[B43LEGACY]: add mac80211-based driver for legacy BCM43xx devices")
Signed-off-by: Natalia Petrova <[email protected]>
---
drivers/net/wireless/broadcom/b43legacy/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/broadcom/b43legacy/main.c b/drivers/net/wireless/broadcom/b43legacy/main.c
index 760136638a95..1ae65679d704 100644
--- a/drivers/net/wireless/broadcom/b43legacy/main.c
+++ b/drivers/net/wireless/broadcom/b43legacy/main.c
@@ -3871,7 +3871,7 @@ static int b43legacy_probe(struct ssb_device *dev,
return err;
err_wireless_exit:
- if (first)
+ if (first && wl)
b43legacy_wireless_exit(dev, wl);
return err;
}
--
2.34.1
On 2/10/23 05:12, Natalia Petrova wrote:
> Function ssb_get_devtypedata(dev) may return null (next call
> B43legacy_WARN_ON(!wl) is used for error handling, including null-value).
> Therefore, a check is added before calling b43legacy_wireless_exit(),
> where the argument containing this value is expected to be dereferenced.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE
>
> Fixes: 75388acd0cd8 ("[B43LEGACY]: add mac80211-based driver for legacy BCM43xx devices")
> Signed-off-by: Natalia Petrova <[email protected]>
> ---
> drivers/net/wireless/broadcom/b43legacy/main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43legacy/main.c b/drivers/net/wireless/broadcom/b43legacy/main.c
> index 760136638a95..1ae65679d704 100644
> --- a/drivers/net/wireless/broadcom/b43legacy/main.c
> +++ b/drivers/net/wireless/broadcom/b43legacy/main.c
> @@ -3871,7 +3871,7 @@ static int b43legacy_probe(struct ssb_device *dev,
> return err;
>
> err_wireless_exit:
> - if (first)
> + if (first && wl)
> b43legacy_wireless_exit(dev, wl);
> return err;
> }
Looks good to me.
Acked-by: Larry Finger <[email protected]>
Thanks,
Larry
On Fri, Feb 10, 2023 at 02:12:28PM +0300, Natalia Petrova wrote:
> Function ssb_get_devtypedata(dev) may return null (next call
> B43legacy_WARN_ON(!wl) is used for error handling, including null-value).
> Therefore, a check is added before calling b43legacy_wireless_exit(),
> where the argument containing this value is expected to be dereferenced.
I see that is true, however, in that case are resources leaked
due to the ieee80211_free_hw() call in b43legacy_wireless_exit()
not being made?
Moreover, aren't there also unguarded dereferences of wl:
1. In the call to b43legacy_one_core_attach(),
which would branch to err_wireless_exit on failure.
2. In the call to schedule_work() just about the out: label.
For the record, and because it seems relevant to give contexxt,
b43legacy_probe() looks like this:
static int b43legacy_probe(struct ssb_device *dev,
const struct ssb_device_id *id)
{
struct b43legacy_wl *wl;
int err;
int first = 0;
wl = ssb_get_devtypedata(dev);
if (!wl) {
/* Probing the first core - setup common struct b43legacy_wl */
first = 1;
err = b43legacy_wireless_init(dev);
if (err)
goto out;
wl = ssb_get_devtypedata(dev);
B43legacy_WARN_ON(!wl);
}
err = b43legacy_one_core_attach(dev, wl);
if (err)
goto err_wireless_exit;
/* setup and start work to load firmware */
INIT_WORK(&wl->firmware_load, b43legacy_request_firmware);
schedule_work(&wl->firmware_load);
out:
return err;
err_wireless_exit:
if (first)
b43legacy_wireless_exit(dev, wl);
return err;
}
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE
>
> Fixes: 75388acd0cd8 ("[B43LEGACY]: add mac80211-based driver for legacy BCM43xx devices")
> Signed-off-by: Natalia Petrova <[email protected]>
> ---
> drivers/net/wireless/broadcom/b43legacy/main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43legacy/main.c b/drivers/net/wireless/broadcom/b43legacy/main.c
> index 760136638a95..1ae65679d704 100644
> --- a/drivers/net/wireless/broadcom/b43legacy/main.c
> +++ b/drivers/net/wireless/broadcom/b43legacy/main.c
> @@ -3871,7 +3871,7 @@ static int b43legacy_probe(struct ssb_device *dev,
> return err;
>
> err_wireless_exit:
> - if (first)
> + if (first && wl)
> b43legacy_wireless_exit(dev, wl);
> return err;
> }
> --
> 2.34.1
>