[PATCH wireless 0/2] wifi: zero-pad SDIO writes to avoid leaking heap data
From: Tristan Madani
Date: Mon Nov 02 2026 - 07:44:04 EST
From: Tristan Madani <tristan@xxxxxxxxxxxxxxxxxxx>
Several wireless drivers round up the length passed to
sdio_memcpy_toio() / sdio_writesb() for alignment purposes but do not
clear the padding bytes. The SDIO controller then reads past the
original buffer into adjacent heap memory, sending stale kernel data to
the wireless device.
Fix brcmfmac (4-byte alignment) and rsi (block alignment) by
zero-filling the gap before the write.
A third patch for rtw88 hits the same class of bug but needs a rebase
and will follow separately.
Tristan Madani (2):
wifi: brcmfmac: zero-pad SDIO write to 4-byte boundary
wifi: rsi: zero-pad SDIO TX to block boundary
drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c | 3 +++
drivers/net/wireless/rsi/rsi_91x_sdio.c | 3 +++
2 files changed, 6 insertions(+)
--
2.47.3