[PATCH AUTOSEL 6.18-5.15] spi: Add NULL check for spi_get_device_id() in spi_get_device_match_data()

[Sasha Levin <sashal@kernel.org>]

From: guoqi0226 <guoqi0226@163.com>

[ Upstream commit f1b061b4d4c6cbf861319ba954caa80145cf018f ]

Prevent NULL pointer dereference when spi_get_device_id() returns NULL,
which can happen when using driver_override without matching SPI ID entry.

Signed-off-by: guoqi0226 <guoqi0226@163.com>
Link: https://patch.msgid.link/20260616103018.105612-3-guoqi0226@163.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

LLM Generated explanations, may be completely bogus:

The author search finished: there are no commits by `guoqi0226` in this
v6.18.44 checkout, so the SPI NULL-check patch isn’t in the tree yet.

That doesn’t change the earlier conclusion — the buggy code is still
present in `drivers/spi/spi.c`, and the fix is a small, low-risk
backport candidate.

**YES**

 drivers/spi/spi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6ea9ac2931cde..abb9e873e3f9f 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -358,12 +358,16 @@ EXPORT_SYMBOL_GPL(spi_get_device_id);
 const void *spi_get_device_match_data(const struct spi_device *sdev)
 {
 	const void *match;
+	const struct spi_device_id *id;
 
 	match = device_get_match_data(&sdev->dev);
 	if (match)
 		return match;
 
-	return (const void *)spi_get_device_id(sdev)->driver_data;
+	id = spi_get_device_id(sdev);
+	if (!id)
+		return NULL;
+	return (const void *)id->driver_data;
 }
 EXPORT_SYMBOL_GPL(spi_get_device_match_data);
 
-- 
2.53.0