[PATCH wireless v2] wifi: wfx: validate MIB read length before copying to caller
From: Aamir Ahmed
Date: Sat Sep 12 2026 - 09:49:10 EST
wfx_hif_read_mib() copies reply->length bytes from the firmware
response into the caller-provided buffer without checking that
reply->length does not exceed val_len. A firmware response with
a length field larger than expected overruns the caller buffer and
reads past the end of the reply allocation.
Replace the dead -ENOMEM check with an active validation that
reply->length fits within val_len before the memcpy.
Fixes: f95a29d40782 ("staging: wfx: add HIF commands helpers")
Assisted-by: LLM
Signed-off-by: Aamir Ahmed <elb12345@xxxxxxxxxxxxx>
---
v2:
- return -EIO rather than -EINVAL, for consistency with the
confirmation-mismatch path above (Jérôme)
- add the Assisted-by: LLM tag (Jérôme)
- Cc LKML (Jérôme)
- correct the Fixes: tag; wfx_hif_read_mib() came in with
f95a29d40782, not the TX-frames commit v1 pointed at
- say what is actually overrun; v1 called it a heap overflow, but
the caller buffer is overrun and the reply allocation over-read
- name the target tree in the subject
v1: https://lore.kernel.org/linux-wireless/AS8P251MB00014841C19595C74C545C80C8B22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Compile-tested only; I have no WFxxx hardware.
drivers/net/wireless/silabs/wfx/hif_tx.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/silabs/wfx/hif_tx.c b/drivers/net/wireless/silabs/wfx/hif_tx.c
index 9f403d275cb1..9efb108bd877 100644
--- a/drivers/net/wireless/silabs/wfx/hif_tx.c
+++ b/drivers/net/wireless/silabs/wfx/hif_tx.c
@@ -207,9 +207,11 @@ int wfx_hif_read_mib(struct wfx_dev *wdev, int vif_id, u16 mib_id, void *val, si
dev_warn(wdev->dev, "%s: confirmation mismatch request\n", __func__);
ret = -EIO;
}
- if (ret == -ENOMEM)
+ if (!ret && le16_to_cpu(reply->length) > val_len) {
dev_err(wdev->dev, "buffer is too small to receive %s (%zu < %d)\n",
wfx_get_mib_name(mib_id), val_len, le16_to_cpu(reply->length));
+ ret = -EIO;
+ }
if (!ret)
memcpy(val, &reply->mib_data, le16_to_cpu(reply->length));
else
base-commit: df2908090cda368b01ff43709f51890076c56157
--
2.55.0