This is a note to let you know that I've just added the patch titled powercap: intel_rapl: Fix a NULL pointer dereference to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powercap-intel_rapl-fix-a-null-pointer-dereference.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b1823793cf740a2758f68fcb492de41a722737ad Author: Zhang Rui <rui.zhang@xxxxxxxxx> Date: Wed Jan 31 19:37:08 2024 +0800 powercap: intel_rapl: Fix a NULL pointer dereference [ Upstream commit 2d1f5006ff95770da502f8cee2a224a1ff83866e ] A NULL pointer dereference is triggered when probing the MMIO RAPL driver on platforms with CPU ID not listed in intel_rapl_common CPU model list. This is because the intel_rapl_common module still probes on such platforms even if 'defaults_msr' is not set after commit 1488ac990ac8 ("powercap: intel_rapl: Allow probing without CPUID match"). Thus the MMIO RAPL rp->priv->defaults is NULL when registering to RAPL framework. Fix the problem by adding sanity check to ensure rp->priv->rapl_defaults is always valid. Fixes: 1488ac990ac8 ("powercap: intel_rapl: Allow probing without CPUID match") Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> Cc: 6.5+ <stable@xxxxxxxxxxxxxxx> # 6.5+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c index 2feed036c1cd4..1a739afd47d96 100644 --- a/drivers/powercap/intel_rapl_common.c +++ b/drivers/powercap/intel_rapl_common.c @@ -759,6 +759,11 @@ static int rapl_config(struct rapl_package *rp) default: return -EINVAL; } + + /* defaults_msr can be NULL on unsupported platforms */ + if (!rp->priv->defaults || !rp->priv->rpi) + return -ENODEV; + return 0; }