spi: spi-mt65xx: Fix NULL pointer access in interrupt handler

[ Upstream commit a20ad45008 ]

The TX buffer in spi_transfer can be a NULL pointer, so the interrupt
handler may end up writing to the invalid memory and cause crashes.

Add a check to trans->tx_buf before using it.

Fixes: 1ce24864bf ("spi: mediatek: Only do dma for 4-byte aligned buffers")
Signed-off-by: Fei Shao <fshao@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://msgid.link/r/20240321070942.1587146-2-fshao@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Fei Shao 2024-03-21 15:08:57 +08:00 committed by Sasha Levin
parent 86c0c154a7
commit 766ec94cc5
1 changed files with 12 additions and 10 deletions

View File

@ -787,17 +787,19 @@ static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, len);
mtk_spi_setup_packet(master);
cnt = mdata->xfer_len / 4;
iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
trans->tx_buf + mdata->num_xfered, cnt);
if (trans->tx_buf) {
cnt = mdata->xfer_len / 4;
iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
trans->tx_buf + mdata->num_xfered, cnt);
remainder = mdata->xfer_len % 4;
if (remainder > 0) {
reg_val = 0;
memcpy(&reg_val,
trans->tx_buf + (cnt * 4) + mdata->num_xfered,
remainder);
writel(reg_val, mdata->base + SPI_TX_DATA_REG);
remainder = mdata->xfer_len % 4;
if (remainder > 0) {
reg_val = 0;
memcpy(&reg_val,
trans->tx_buf + (cnt * 4) + mdata->num_xfered,
remainder);
writel(reg_val, mdata->base + SPI_TX_DATA_REG);
}
}
mtk_spi_enable_transfer(master);