Thread (10 messages) 10 messages, 5 authors, 2025-10-21
STALE270d

[PATCH] mfd: macsmc: Initialize mutex

From: Janne Grunau <j@jannau.net>
Date: 2025-09-25 20:33:37
Also in: asahi, lkml
Subsystem: arm/apple machine support, multifunction devices (mfd), the rest · Maintainers: Sven Peter, Janne Grunau, Lee Jones, Linus Torvalds

Struct apple_smc's mutex was not initialized before use. Surprisingly
this only resulted in occasional NULL pointer dereferences in
apple_smc_read() calls from the probe() functions of sub devices.

Fixes: e038d985c9823 ("mfd: Add Apple Silicon System Management Controller")
Signed-off-by: Janne Grunau <j@jannau.net>
---
 drivers/mfd/macsmc.c | 1 +
 1 file changed, 1 insertion(+)
diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c
index 870c8b2028a8fc0e905c8934c2636824cbe5d527..3a117cf19145e86b642f40dc165b542b8df69070 100644
--- a/drivers/mfd/macsmc.c
+++ b/drivers/mfd/macsmc.c
@@ -413,6 +413,7 @@ static int apple_smc_probe(struct platform_device *pdev)
 	if (!smc)
 		return -ENOMEM;
 
+	mutex_init(&smc->mutex);
 	smc->dev = &pdev->dev;
 	smc->sram_base = devm_platform_get_and_ioremap_resource(pdev, 1, &smc->sram);
 	if (IS_ERR(smc->sram_base))
---
base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
change-id: 20250925-macsmc-mutex_init-80d7cb2aacfa

Best regards,
-- 
Janne Grunau [off-list ref]

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help