2023-03-22 16:44:24

by Lorenzo Bianconi

Subject: [PATCH v3] wireless: mt76: mt7921: Fix use-after-free in fw features query.

From: Ben Greear <[email protected]>

Stop referencing 'features' memory after release_firmware is called.

Fixes this crash:

RIP: 0010:mt7921_check_offload_capability+0x17d
mt7921_pci_probe+0xca/0x4b0
...

Signed-off-by: Ben Greear <[email protected]>
Signed-off-by: Lorenzo Bianconi <[email protected]>
---
Changes since v2:
- get rid of the comments
---
drivers/net/wireless/mediatek/mt76/mt7921/init.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/init.c b/drivers/net/wireless/mediatek/mt76/mt7921/init.c
index 80c71acfe159..cc94531185da 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/init.c
@@ -171,12 +171,12 @@ mt7921_mac_init_band(struct mt7921_dev *dev, u8 band)

u8 mt7921_check_offload_capability(struct device *dev, const char *fw_wm)
{
- struct mt7921_fw_features *features = NULL;
const struct mt76_connac2_fw_trailer *hdr;
struct mt7921_realease_info *rel_info;
const struct firmware *fw;
int ret, i, offset = 0;
const u8 *data, *end;
+ u8 offload_caps = 0;

ret = request_firmware(&fw, fw_wm, dev);
if (ret)
@@ -208,7 +208,10 @@ u8 mt7921_check_offload_capability(struct device *dev, const char *fw_wm)
data += sizeof(*rel_info);

if (rel_info->tag == MT7921_FW_TAG_FEATURE) {
+ struct mt7921_fw_features *features;
+
features = (struct mt7921_fw_features *)data;
+ offload_caps = features->data;
break;
}

@@ -218,7 +221,7 @@ u8 mt7921_check_offload_capability(struct device *dev, const char *fw_wm)
out:
release_firmware(fw);

- return features ? features->data : 0;
+ return offload_caps;
}
EXPORT_SYMBOL_GPL(mt7921_check_offload_capability);

--
2.39.2

2023-03-22 20:59:58

by Felix Fietkau

Subject: Re: [PATCH v3] wireless: mt76: mt7921: Fix use-after-free in fw features query.

On 22.03.23 17:37, Lorenzo Bianconi wrote:
> From: Ben Greear <[email protected]>
>
> Stop referencing 'features' memory after release_firmware is called.
>
> Fixes this crash:
>
> RIP: 0010:mt7921_check_offload_capability+0x17d
> mt7921_pci_probe+0xca/0x4b0
> ...
>
> Signed-off-by: Ben Greear <[email protected]>
> Signed-off-by: Lorenzo Bianconi <[email protected]>
Acked-by: Felix Fietkau <[email protected]>

- Felix

2023-03-24 07:24:06

by Kalle Valo

Subject: Re: [PATCH v3] wireless: mt76: mt7921: Fix use-after-free in fw features query.

Felix Fietkau <[email protected]> writes:

> On 22.03.23 17:37, Lorenzo Bianconi wrote:
>> From: Ben Greear <[email protected]>
>>
>> Stop referencing 'features' memory after release_firmware is called.
>>
>> Fixes this crash:
>>
>> RIP: 0010:mt7921_check_offload_capability+0x17d
>> mt7921_pci_probe+0xca/0x4b0
>> ...
>>
>> Signed-off-by: Ben Greear <[email protected]>
>> Signed-off-by: Lorenzo Bianconi <[email protected]>

The title should have "wifi:", not "wireless:".

> Acked-by: Felix Fietkau <[email protected]>

Felix, do you mean I should take this to wireless tree?

--
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

2023-03-24 10:30:28

by Felix Fietkau

Subject: Re: [PATCH v3] wireless: mt76: mt7921: Fix use-after-free in fw features query.

On 24.03.23 08:17, Kalle Valo wrote:
> Felix Fietkau <[email protected]> writes:
>
>> On 22.03.23 17:37, Lorenzo Bianconi wrote:
>>> From: Ben Greear <[email protected]>
>>>
>>> Stop referencing 'features' memory after release_firmware is called.
>>>
>>> Fixes this crash:
>>>
>>> RIP: 0010:mt7921_check_offload_capability+0x17d
>>> mt7921_pci_probe+0xca/0x4b0
>>> ...
>>>
>>> Signed-off-by: Ben Greear <[email protected]>
>>> Signed-off-by: Lorenzo Bianconi <[email protected]>
>
> The title should have "wifi:", not "wireless:".
>
>> Acked-by: Felix Fietkau <[email protected]>
>
> Felix, do you mean I should take this to wireless tree?
Sure

- Felix

2023-03-31 15:09:29

by Kalle Valo

Subject: Re: [v3] wifi: mt76: mt7921: Fix use-after-free in fw features query.

Lorenzo Bianconi <[email protected]> wrote:

> From: Ben Greear <[email protected]>
>
> Stop referencing 'features' memory after release_firmware is called.
>
> Fixes this crash:
>
> RIP: 0010:mt7921_check_offload_capability+0x17d
> mt7921_pci_probe+0xca/0x4b0
> ...
>
> Signed-off-by: Ben Greear <[email protected]>
> Signed-off-by: Lorenzo Bianconi <[email protected]>
> Acked-by: Felix Fietkau <[email protected]>

Patch applied to wireless.git, thanks.

2ceb76f734e3 wifi: mt76: mt7921: Fix use-after-free in fw features query.

--
https://patchwork.kernel.org/project/linux-wireless/patch/51fd8f76494348aa9ecbf0abc471ebe47a983dfd.1679502607.git.lorenzo@kernel.org/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches