Move the assignment of the transfer pointer from curr_xfer inside the
spinlock critical section in both handle_cpu_based_xfer() and
handle_dma_based_xfer().
Previously, curr_xfer was read before acquiring the lock, creating a
window where the timeout path could clear curr_xfer between reading it
and using it. By moving the read inside the lock, the handlers are
guaranteed to see a consistent value that cannot be modified by the
timeout path.
Fixes: 921fc1838fb0 ("spi: tegra210-quad: Add support for Tegra210 QSPI controller")
Signed-off-by: Breno Leitao <leitao@debian.org>
---
drivers/spi/spi-tegra210-quad.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index f0408c0b4b981..ee291b9e9e9c0 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -1440,10 +1440,11 @@ static int tegra_qspi_transfer_one_message(struct spi_controller *host,
static irqreturn_t handle_cpu_based_xfer(struct tegra_qspi *tqspi)
{
- struct spi_transfer *t = tqspi->curr_xfer;
+ struct spi_transfer *t;
unsigned long flags;
spin_lock_irqsave(&tqspi->lock, flags);
+ t = tqspi->curr_xfer;
if (tqspi->tx_status || tqspi->rx_status) {
tegra_qspi_handle_error(tqspi);
@@ -1474,7 +1475,7 @@ static irqreturn_t handle_cpu_based_xfer(struct tegra_qspi *tqspi)
static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
{
- struct spi_transfer *t = tqspi->curr_xfer;
+ struct spi_transfer *t;
unsigned int total_fifo_words;
unsigned long flags;
long wait_status;
@@ -1513,6 +1514,7 @@ static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
}
spin_lock_irqsave(&tqspi->lock, flags);
+ t = tqspi->curr_xfer;
if (num_errors) {
tegra_qspi_dma_unmap_xfer(tqspi, t);
--
2.47.3