Initialize struct apple_smc's mutex in apple_smc_probe(). Using the mutex uninitialized surprisingly resulted only 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") Cc: stable@vger.kernel.org Signed-off-by: Janne Grunau j@jannau.net --- Changes in v2: - rewritten commit message - added missing Cc: stable - rebased onto v6.19-rc1 - Link to v1: https://lore.kernel.org/r/20250925-macsmc-mutex_init-v1-1-416e9e644735@janna... --- drivers/mfd/macsmc.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c index e3893e255ce5e4bb4832d80ad1fc002d413a291a..3015e8d36d6e5bfdcea342c7d05a7b34788d7845 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: 8f0b4cce4481fb22653697cced8d0d04027cb1e8 change-id: 20250925-macsmc-mutex_init-80d7cb2aacfa

Best regards,