From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Felix Gu <ustc.gu@gmail.com>,
	"=?UTF-8?q?J . =20Neusch=C3=A4fer?=" <j.ne@posteo.net>,
	Mark Brown <broonie@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.18 593/641] spi: wpcm-fiu: Fix potential NULL pointer dereference in wpcm_fiu_probe()
Date: Tue, 24 Feb 2026 17:25:19 -0800
Message-ID: <20260225012402.882941778@linuxfoundation.org>
In-Reply-To: <20260225012348.915798704@linuxfoundation.org>
References: <20260225012348.915798704@linuxfoundation.org>
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6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Felix Gu <ustc.gu@gmail.com>

[ Upstream commit 888a0a802c467bbe34a42167bdf9d7331333440a ]

platform_get_resource_byname() can return NULL, which would cause a crash
when passed the pointer to resource_size().

Move the fiu->memory_size assignment after the error check for
devm_ioremap_resource() to prevent the potential NULL pointer dereference.

Fixes: 9838c182471e ("spi: wpcm-fiu: Add direct map support")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: J. Neuschäfer <j.ne@posteo.net>
Link: https://patch.msgid.link/20260212-wpcm-v1-1-5b7c4f526aac@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-wpcm-fiu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-wpcm-fiu.c b/drivers/spi/spi-wpcm-fiu.c
index a9aee2a6c7dcb..c47b56f0933f1 100644
--- a/drivers/spi/spi-wpcm-fiu.c
+++ b/drivers/spi/spi-wpcm-fiu.c
@@ -459,11 +459,11 @@ static int wpcm_fiu_probe(struct platform_device *pdev)
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "memory");
 	fiu->memory = devm_ioremap_resource(dev, res);
-	fiu->memory_size = min_t(size_t, resource_size(res), MAX_MEMORY_SIZE_TOTAL);
 	if (IS_ERR(fiu->memory))
 		return dev_err_probe(dev, PTR_ERR(fiu->memory),
 			       "Failed to map flash memory window\n");
 
+	fiu->memory_size = min_t(size_t, resource_size(res), MAX_MEMORY_SIZE_TOTAL);
 	fiu->shm_regmap = syscon_regmap_lookup_by_phandle_optional(dev->of_node, "nuvoton,shm");
 
 	wpcm_fiu_hw_init(fiu);
-- 
2.51.0