[PATCH v2 09/13] dmaengine: ste_dma40: Fix memcpy channel parsing

[Linus Walleij <linusw@kernel.org>]

d40_of_probe() validates the memcpy-channels property against
D40_MEMCPY_MAX_CHANS, but reads the property directly into
dma40_memcpy_channels. That array has fewer entries, so a long property
can overwrite adjacent data.

Validate the property length against ARRAY_SIZE(dma40_memcpy_channels)
before reading it into the array.

Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/dmaengine/20260819225215.5EA2F1F000E9@smtp.kernel.org/
Assisted-by: Codex:gpt-5-5
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 drivers/dma/ste_dma40.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 8cf73b37f8bf..4e840846466b 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -3470,7 +3470,8 @@ static int __init d40_of_probe(struct device *dev,
 	list = of_get_property(np, "memcpy-channels", &num_memcpy);
 	num_memcpy /= sizeof(*list);
 
-	if (num_memcpy > D40_MEMCPY_MAX_CHANS || num_memcpy <= 0) {
+	if (num_memcpy > ARRAY_SIZE(dma40_memcpy_channels) ||
+	    num_memcpy <= 0) {
 		d40_err(dev,
 			"Invalid number of memcpy channels specified (%d)\n",
 			num_memcpy);

-- 
2.55.0