Add the missing sanity checks and move the 255-byte build-id buffer off the stack to avoid leaking stack data through debugfs in case the build-info reply is malformed.

Fixes: c0187b0bd3e9 ("Bluetooth: btqca: Add support to read FW build version for WCN3991 BTSoC") Cc: stable@vger.kernel.org # 5.12 Signed-off-by: Johan Hovold johan+linaro@kernel.org --- drivers/bluetooth/btqca.c | 25 +++++++++++++++++++++---- drivers/bluetooth/btqca.h | 1 - 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c index 38a770278103..a508d79d9aaa 100644 --- a/drivers/bluetooth/btqca.c +++ b/drivers/bluetooth/btqca.c @@ -99,7 +99,8 @@ static int qca_read_fw_build_info(struct hci_dev *hdev) { struct sk_buff *skb; struct edl_event_hdr *edl; - char cmd, build_label[QCA_FW_BUILD_VER_LEN]; + char *build_label; + char cmd; int build_lbl_len, err = 0;

bt_dev_dbg(hdev, "QCA read fw build info"); @@ -114,6 +115,11 @@ static int qca_read_fw_build_info(struct hci_dev *hdev) return err; }

+ if (skb->len < sizeof(*edl)) { + err = -EILSEQ; + goto out; + } + edl = (struct edl_event_hdr *)(skb->data); if (!edl) { bt_dev_err(hdev, "QCA read fw build info with no header"); @@ -129,14 +135,25 @@ static int qca_read_fw_build_info(struct hci_dev *hdev) goto out; }

+ if (skb->len < sizeof(*edl) + 1) { + err = -EILSEQ; + goto out; + } + build_lbl_len = edl->data[0]; - if (build_lbl_len <= QCA_FW_BUILD_VER_LEN - 1) { - memcpy(build_label, edl->data + 1, build_lbl_len); - *(build_label + build_lbl_len) = '\0'; + + if (skb->len < sizeof(*edl) + 1 + build_lbl_len) { + err = -EILSEQ; + goto out; }

+ build_label = kstrndup(&edl->data[1], build_lbl_len, GFP_KERNEL); + if (!build_label) + goto out; + hci_set_fw_info(hdev, "%s", build_label);

+ kfree(build_label); out: kfree_skb(skb); return err; diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h index 49ad668d0d0b..215433fd76a1 100644 --- a/drivers/bluetooth/btqca.h +++ b/drivers/bluetooth/btqca.h @@ -48,7 +48,6 @@ #define get_soc_ver(soc_id, rom_ver) \ ((le32_to_cpu(soc_id) << 16) | (le16_to_cpu(rom_ver)))

-#define QCA_FW_BUILD_VER_LEN 255 #define QCA_HSP_GF_SOC_ID 0x1200 #define QCA_HSP_GF_SOC_MASK 0x0000ff00