7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weibin Liu [ Upstream commit ef9690269999ddf9b204731baca1bd6b7aea1aa7 ] transfer_one_message_b0() falls back to a 10-byte stack buffer for transfers which carry no TX data and points both in_buffer and out_buffer into it. With a transfer longer than 10 bytes the SDMA branch of the loop moves up to MRVL_XFER_QWORD_COUNT * MRVL_XFER_QWORD_BYTECOUNT (256) bytes through those pointers and then advances them by the same amount, so both directions overflow the scratch buffer: a read transaction copies SDMA data past the end of the buffer, a write transaction sends stack contents from beyond it to the SPI bus. Size the scratch buffer for the largest chunk the loop can request, keep the buffer pointers pinned to it when the message does not carry the corresponding TX or RX data, and only advance the pointers which reference real transfer buffers. Also zero-initialize the scratch buffer so that padding bytes sent for TX-less transfers no longer leak uninitialized stack contents. Fixes: 5cb7651f78e1 ("Marvell HW overlay support for Cadence xSPI") Cc: stable@vger.kernel.org # 6.11+ Signed-off-by: Weibin Liu Link: https://patch.msgid.link/20260929081146.41041-3-liuwb@xiaopeng.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-cadence-xspi.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c index 1f1cd45359d34..3687853e4ce4e 100644 --- a/drivers/spi/spi-cadence-xspi.c +++ b/drivers/spi/spi-cadence-xspi.c @@ -268,6 +268,7 @@ #define MRVL_XFER_FUNC_START BIT(0) #define MRVL_XFER_QWORD_COUNT 32 #define MRVL_XFER_QWORD_BYTECOUNT 8 +#define MRVL_XFER_MAX_LEN (MRVL_XFER_QWORD_COUNT * MRVL_XFER_QWORD_BYTECOUNT) #define MRVL_XSPI_POLL_TIMEOUT_US 1000 #define MRVL_XSPI_POLL_DELAY_US 10 @@ -1107,7 +1108,7 @@ static int cdns_xspi_transfer_one_message_b0(struct spi_controller *controller, struct spi_device *spi = m->spi; struct spi_transfer *t = NULL; - const unsigned int max_len = MRVL_XFER_QWORD_BYTECOUNT * MRVL_XFER_QWORD_COUNT; + const unsigned int max_len = MRVL_XFER_MAX_LEN; int current_transfer_len; int cs = spi_get_chipselect(spi, 0); int cs_change = 0; @@ -1130,13 +1131,16 @@ static int cdns_xspi_transfer_one_message_b0(struct spi_controller *controller, list_for_each_entry(t, &m->transfers, transfer_list) { u8 *txd = (u8 *) t->tx_buf; u8 *rxd = (u8 *) t->rx_buf; - u8 data[10]; + u8 data[MRVL_XFER_MAX_LEN] = {0}; u32 cmd_regs[6]; if (!txd) txd = data; - cdns_xspi->in_buffer = txd + 1; + if (rxd) + cdns_xspi->in_buffer = rxd; + else + cdns_xspi->in_buffer = data; cdns_xspi->out_buffer = txd + 1; while (t->len) { @@ -1163,8 +1167,10 @@ static int cdns_xspi_transfer_one_message_b0(struct spi_controller *controller, if (!cdns_xspi_is_stig_ready(cdns_xspi, true)) return -EIO; - cdns_xspi->in_buffer += current_transfer_len; - cdns_xspi->out_buffer += current_transfer_len; + if (rxd) + cdns_xspi->in_buffer += current_transfer_len; + if (t->tx_buf) + cdns_xspi->out_buffer += current_transfer_len; } if (rxd) { -- 2.53.0