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

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 <greearb@candelatech.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Acked-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/51fd8f76494348aa9ecbf0abc471ebe47a983dfd.1679502607.git.lorenzo@kernel.org
This commit is contained in:
Ben Greear 2023-03-22 17:37:17 +01:00 committed by Kalle Valo
parent e4efa515d5
commit 2ceb76f734
1 changed files with 5 additions and 2 deletions

View File

@ -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);