From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Aelin Reidel <aelin@mainlining.org>,
	Clayton Craft <craftyguy@postmarketos.org>,
	Sven Peter <sven@kernel.org>,
	Srinivas Kandagatla <srini@kernel.org>
Subject: [PATCH 6.18 161/250] nvmem: apple-spmi-nvmem: wrap regmap calls to satisfy CFI
Date: Mon, 17 Aug 2026 15:32:02 +0200
Message-ID: <20260817132543.175847018@linuxfoundation.org>
In-Reply-To: <20260817132536.466235697@linuxfoundation.org>
References: <20260817132536.466235697@linuxfoundation.org>
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6.18-stable review patch.  If anyone has any objections, please let me know.

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

From: Aelin Reidel <aelin@mainlining.org>

commit ff10b6db0ab75b132aed69ab144ac04f63ef9bdb upstream.

The Apple SPMI NVMEM driver previously cast regmap_bulk_read/write to
void * when assigning them to nvmem_config's reg_read/reg_write
function pointers.

This cast breaks the expected function signature of nvmem_reg_read_t
and nvmem_reg_write_t. With CFI enabled, indirect calls through
these pointers fail:

  CFI failure at nvmem_reg_write+0x194/0x1e4 (target: regmap_bulk_write+0x0/0x2c8; expected type: 0x83a189c3)
  ...
  Call trace:
   nvmem_reg_write+0x194/0x1e4 (P)
   __nvmem_cell_entry_write+0x298/0x2e8
   nvmem_cell_write+0x24/0x34
   macsmc_reboot_probe+0x1dc/0x454 [macsmc_reboot]
  ...

Introduce thin wrapper functions with the correct nvmem function
pointer types to satisfy the CFI checks.

Fixes: fe91c24a551c ("nvmem: Add apple-spmi-nvmem driver")
Signed-off-by: Aelin Reidel <aelin@mainlining.org>
Reported-by: Clayton Craft <craftyguy@postmarketos.org>
Tested-by: Clayton Craft <craftyguy@postmarketos.org>
Reviewed-by: Sven Peter <sven@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260724223404.629248-2-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/nvmem/apple-spmi-nvmem.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/nvmem/apple-spmi-nvmem.c b/drivers/nvmem/apple-spmi-nvmem.c
index 88614005d5ce..7acb0c07d6ab 100644
--- a/drivers/nvmem/apple-spmi-nvmem.c
+++ b/drivers/nvmem/apple-spmi-nvmem.c
@@ -18,6 +18,22 @@ static const struct regmap_config apple_spmi_regmap_config = {
 	.max_register	= 0xffff,
 };
 
+static int apple_spmi_nvmem_read(void *priv, unsigned int offset, void *val,
+				 size_t bytes)
+{
+	struct regmap *map = priv;
+
+	return regmap_bulk_read(map, offset, val, bytes);
+}
+
+static int apple_spmi_nvmem_write(void *priv, unsigned int offset, void *val,
+				  size_t bytes)
+{
+	struct regmap *map = priv;
+
+	return regmap_bulk_write(map, offset, val, bytes);
+}
+
 static int apple_spmi_nvmem_probe(struct spmi_device *sdev)
 {
 	struct regmap *regmap;
@@ -28,8 +44,8 @@ static int apple_spmi_nvmem_probe(struct spmi_device *sdev)
 		.word_size = 1,
 		.stride = 1,
 		.size = 0xffff,
-		.reg_read = (void *)regmap_bulk_read,
-		.reg_write = (void *)regmap_bulk_write,
+		.reg_read = apple_spmi_nvmem_read,
+		.reg_write = apple_spmi_nvmem_write,
 	};
 
 	regmap = devm_regmap_init_spmi_ext(sdev, &apple_spmi_regmap_config);
-- 
2.55.0