Commit 2ceb76f7 authored by Ben Greear's avatar Ben Greear Committed by Kalle Valo
Browse files

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: default avatarBen Greear <greearb@candelatech.com>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Acked-by: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/51fd8f76494348aa9ecbf0abc471ebe47a983dfd.1679502607.git.lorenzo@kernel.org
parent e4efa515

drivers/net/wireless/mediatek/mt76/mt7921/init.c

+5 −2
Original line number Diff line number Diff line
@@ -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);