[PATCH 6.1 66/69] spi: tegra210-quad: Protect curr_xfer in tegra_qspi_combined_seq_xfer

Greg Kroah-Hartman
2026-02-09T14:45:05Z

From: Breno Leitao <leitao@debian.org>

[ Upstream commit bf4528ab28e2bf112c3a2cdef44fd13f007781cd ]

The curr_xfer field is read by the IRQ handler without holding the lock
to check if a transfer is in progress. When clearing curr_xfer in the
combined sequence transfer loop, protect it with the spinlock to prevent
a race with the interrupt handler.

Protect the curr_xfer clearing at the exit path of
tegra_qspi_combined_seq_xfer() with the spinlock to prevent a race
with the interrupt handler that reads this field.

Without this protection, the IRQ handler could read a partially updated
curr_xfer value, leading to NULL pointer dereference or use-after-free.

Fixes: b4e002d8a7ce ("spi: tegra210-quad: Fix timeout handling")
Signed-off-by: Breno Leitao <leitao@debian.org>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260126-tegra_xfer-v2-4-6d2115e4f387@debian.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-tegra210-quad.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index d3d3e698bffa1..a06609a43c7f1 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -1063,6 +1063,7 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
u32 address_value = 0;
u32 cmd_config = 0, addr_config = 0;
u8 cmd_value = 0, val = 0;
+ unsigned long flags;

/* Enable Combined sequence mode */
val = tegra_qspi_readl(tqspi, QSPI_GLOBAL_CONFIG);
@@ -1169,13 +1170,17 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
tegra_qspi_transfer_end(spi);
spi_transfer_delay_exec(xfer);
}
+ spin_lock_irqsave(&tqspi->lock, flags);
tqspi->curr_xfer = NULL;
+ spin_unlock_irqrestore(&tqspi->lock, flags);
transfer_phase++;
}
ret = 0;

exit:
+ spin_lock_irqsave(&tqspi->lock, flags);
tqspi->curr_xfer = NULL;
+ spin_unlock_irqrestore(&tqspi->lock, flags);
msg->status = ret;

return ret;
--
2.51.0