The kzalloc() in brcmf_pmksa_v3_op() will return null if the
physical memory has run out. As a result, if we dereference
the null value, the null pointer dereference bug will happen.
Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails
for pmk_op.
Fixes: a96202acaea4 ("wifi: brcmfmac: cfg80211: Add support for PMKID_V3 operations")
Signed-off-by: Duoming Zhou <[email protected]>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 28d6a30cc01..3b420b33188 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -4322,6 +4322,10 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa,
int ret;
pmk_op = kzalloc(sizeof(*pmk_op), GFP_KERNEL);
+ if (!pmk_op) {
+ ret = -ENOMEM;
+ goto out;
+ }
pmk_op->version = cpu_to_le16(BRCMF_PMKSA_VER_3);
if (!pmksa) {
@@ -4340,6 +4344,7 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa,
pmk_op->length = cpu_to_le16(length);
ret = brcmf_fil_iovar_data_set(ifp, "pmkid_info", pmk_op, sizeof(*pmk_op));
+out:
kfree(pmk_op);
return ret;
}
--
2.17.1
On 2/27/2024 9:06 AM, Duoming Zhou wrote:
> The kzalloc() in brcmf_pmksa_v3_op() will return null if the
> physical memory has run out. As a result, if we dereference
> the null value, the null pointer dereference bug will happen.
>
> Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails
> for pmk_op.
NAK (see below)
Also this issue was reported earlier by Joe Perches. Not sure if he
wants to be mentioned as such.
> Fixes: a96202acaea4 ("wifi: brcmfmac: cfg80211: Add support for PMKID_V3 operations")
> Signed-off-by: Duoming Zhou <[email protected]>
> ---
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> index 28d6a30cc01..3b420b33188 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> @@ -4322,6 +4322,10 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa,
> int ret;
>
> pmk_op = kzalloc(sizeof(*pmk_op), GFP_KERNEL);
> + if (!pmk_op) {
> + ret = -ENOMEM;
> + goto out;
> + }
There is really no need to introduce a new label for this. Although you
can kfree() a NULL pointer there is no need to do so when you know
already it is NULL. Just return -ENOMEM and be done with it.
Regards,
Arend
> pmk_op->version = cpu_to_le16(BRCMF_PMKSA_VER_3);
>
> if (!pmksa) {
> @@ -4340,6 +4344,7 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa,
> pmk_op->length = cpu_to_le16(length);
>
> ret = brcmf_fil_iovar_data_set(ifp, "pmkid_info", pmk_op, sizeof(*pmk_op));
> +out:
> kfree(pmk_op);
> return ret;
> }
On Tue, 2024-02-27 at 20:40 +0100, Arend van Spriel wrote:
> On 2/27/2024 12:42 PM, Joe Perches wrote:
> > On Tue, 2024-02-27 at 12:21 +0100, Arend van Spriel wrote:
> > > On 2/27/2024 9:06 AM, Duoming Zhou wrote:
> > > > The kzalloc() in brcmf_pmksa_v3_op() will return null if the
> > > > physical memory has run out. As a result, if we dereference
> > > > the null value, the null pointer dereference bug will happen.
> > > >
> > > > Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails
> > > > for pmk_op.
> > >
> > > NAK (see below)
> > >
> > > Also this issue was reported earlier by Joe Perches. Not sure if he
> > > wants to be mentioned as such.
> >
> > I think it's unimportant to be mentioned.
> >
> > I think it's more important that the code be researched
> > that the simple return of -ENOMEM the appropriate fix
> > and is handled by all possible callers of the function.
>
> Right. That is what I did after which I replied on Feb 18 to your email.
>
> https://lore.kernel.org/all/[email protected]/
>
Right, I did that as well, but I didn't look up
the entire calling tree.
It likely works. It's also likely better than
the write through of the null pointer.
On 2/27/2024 12:42 PM, Joe Perches wrote:
> On Tue, 2024-02-27 at 12:21 +0100, Arend van Spriel wrote:
>> On 2/27/2024 9:06 AM, Duoming Zhou wrote:
>>> The kzalloc() in brcmf_pmksa_v3_op() will return null if the
>>> physical memory has run out. As a result, if we dereference
>>> the null value, the null pointer dereference bug will happen.
>>>
>>> Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails
>>> for pmk_op.
>>
>> NAK (see below)
>>
>> Also this issue was reported earlier by Joe Perches. Not sure if he
>> wants to be mentioned as such.
>
> I think it's unimportant to be mentioned.
>
> I think it's more important that the code be researched
> that the simple return of -ENOMEM the appropriate fix
> and is handled by all possible callers of the function.
Right. That is what I did after which I replied on Feb 18 to your email.
https://lore.kernel.org/all/[email protected]/
Regards,
Arend
>>
>>> Fixes: a96202acaea4 ("wifi: brcmfmac: cfg80211: Add support for PMKID_V3 operations")
>>> Signed-off-by: Duoming Zhou <[email protected]>
>>> ---
>>> drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++
>>> 1 file changed, 5 insertions(+)
>>>
>>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.cq b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
>>> index 28d6a30cc01..3b420b33188 100644
>>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
>>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
>>> @@ -4322,6 +4322,10 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa,
>>> int ret;
>>>
>>> pmk_op = kzalloc(sizeof(*pmk_op), GFP_KERNEL);
>>> + if (!pmk_op) {
>>> + ret = -ENOMEM;
>>> + goto out;
>>> + }
>>
>> There is really no need to introduce a new label for this. Although you
>> can kfree() a NULL pointer there is no need to do so when you know
>> already it is NULL. Just return -ENOMEM and be done with it.
>>
>> Regards,
>> Arend
>>
>>> pmk_op->version = cpu_to_le16(BRCMF_PMKSA_VER_3);
>>>
>>> if (!pmksa) {
>>> @@ -4340,6 +4344,7 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa,
>>> pmk_op->length = cpu_to_le16(length);
>>>
>>> ret = brcmf_fil_iovar_data_set(ifp, "pmkid_info", pmk_op, sizeof(*pmk_op));
>>> +out:
>>> kfree(pmk_op);
>>> return ret;
>>> }
>