A shift-out-of-bounds issue was identified by UBSAN in the
tegra_qspi_fill_tx_fifo_from_client_txbuf() function.

	 UBSAN: shift-out-of-bounds in drivers/spi/spi-tegra210-quad.c:345:27
	 shift exponent 32 is too large for 32-bit type 'u32' (aka 'unsigned int')
	 Call trace:
	  tegra_qspi_start_cpu_based_transfer

The problem arises when shifting the contents of tx_buf left by 8 times
the value of i, which can exceed 4 and result in an exponent larger than
32 bits.

Resolve this by restrict the value of i to be less than 4, preventing
the shift operation from overflowing.

Signed-off-by: Breno Leitao <leitao@debian.org>
Fixes: 921fc1838fb0 ("spi: tegra210-quad: Add support for Tegra210 QSPI controller")
---
 drivers/spi/spi-tegra210-quad.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index afbd64a217eb..43f11b0e9e76 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -341,7 +341,7 @@ tegra_qspi_fill_tx_fifo_from_client_txbuf(struct tegra_qspi *tqspi, struct spi_t
 		for (count = 0; count < max_n_32bit; count++) {
 			u32 x = 0;
 
-			for (i = 0; len && (i < bytes_per_word); i++, len--)
+			for (i = 0; len && (i < min(4, bytes_per_word)); i++, len--)
 				x |= (u32)(*tx_buf++) << (i * 8);
 			tegra_qspi_writel(tqspi, x, QSPI_TX_FIFO);
 		}
-- 
2.43.5

On Fri, 04 Oct 2024 05:53:59 -0700, Breno Leitao wrote:
> A shift-out-of-bounds issue was identified by UBSAN in the
> tegra_qspi_fill_tx_fifo_from_client_txbuf() function.
> 
> 	 UBSAN: shift-out-of-bounds in drivers/spi/spi-tegra210-quad.c:345:27
> 	 shift exponent 32 is too large for 32-bit type 'u32' (aka 'unsigned int')
> 	 Call trace:
> 	  tegra_qspi_start_cpu_based_transfer
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: tegra210-quad: Avoid shift-out-of-bounds
      commit: f399051ec1ff02e74ae5c2517aed2cc486fd005b

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark