[PATCH v2] spi: Fix invalid sgs value

[PATCH v2] spi: Fix invalid sgs value

[Biju Das]

max_seg_size is unsigned int and it can have a value up to 2^32
(for eg:-RZ_DMAC driver sets dma_set_max_seg_size as U32_MAX)
When this value is used in min_t() as an integer type, it becomes
-1 and the value of sgs becomes 0.

Fix this issue by replacing the 'int' data type with 'unsigned int'
in min_t().

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2:
 * Removed the cast for ctlr->max_dma_len in min_t()
---
 drivers/spi/spi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 4599b121d744..d96082dc3340 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1019,10 +1019,10 @@ int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
 	int i, ret;
 
 	if (vmalloced_buf || kmap_buf) {
-		desc_len = min_t(int, max_seg_size, PAGE_SIZE);
+		desc_len = min_t(unsigned int, max_seg_size, PAGE_SIZE);
 		sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
 	} else if (virt_addr_valid(buf)) {
-		desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
+		desc_len = min_t(unsigned int, max_seg_size, ctlr->max_dma_len);
 		sgs = DIV_ROUND_UP(len, desc_len);
 	} else {
 		return -EINVAL;
-- 
2.17.1

Re: [PATCH v2] spi: Fix invalid sgs value

[Geert Uytterhoeven]

On Mon, Mar 7, 2022 at 7:48 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> max_seg_size is unsigned int and it can have a value up to 2^32
> (for eg:-RZ_DMAC driver sets dma_set_max_seg_size as U32_MAX)
> When this value is used in min_t() as an integer type, it becomes
> -1 and the value of sgs becomes 0.
>
> Fix this issue by replacing the 'int' data type with 'unsigned int'
> in min_t().
>
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> v1->v2:
>  * Removed the cast for ctlr->max_dma_len in min_t()

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2] spi: Fix invalid sgs value

[Mark Brown]

On Mon, 7 Mar 2022 18:48:43 +0000, Biju Das wrote:
> max_seg_size is unsigned int and it can have a value up to 2^32
> (for eg:-RZ_DMAC driver sets dma_set_max_seg_size as U32_MAX)
> When this value is used in min_t() as an integer type, it becomes
> -1 and the value of sgs becomes 0.
> 
> Fix this issue by replacing the 'int' data type with 'unsigned int'
> in min_t().
> 
> [...]

Applied to

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

Thanks!

[1/1] spi: Fix invalid sgs value
      commit: 1a4e53d2fc4f68aa654ad96d13ad042e1a8e8a7d

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