From 8e81b9cd6e95188d12c9cc25d40b61dd5ea05ace Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Wed, 23 Apr 2025 08:18:45 -0500 Subject: [PATCH] drivers/platform/x86/amd: pmf: Check for invalid Smart PC Policies MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 376a8c2a14439 ("platform/x86/amd/pmf: Update PMF Driver for Compatibility with new PMF-TA") added support for platforms that support an updated TA, however it also exposed a number of platforms that although they have support for the updated TA don't actually populate a policy binary. Add an explicit check that the policy binary isn't empty before initializing the TA. Reported-by: Christian Heusel Closes: https://lore.kernel.org/platform-driver-x86/ae644428-5bf2-4b30-81ba-0b259ed3449b@heusel.eu/ Fixes: 376a8c2a14439 ("platform/x86/amd/pmf: Update PMF Driver for Compatibility with new PMF-TA") Signed-off-by: Mario Limonciello Tested-by: Christian Heusel Link: https://lore.kernel.org/r/20250423132002.3984997-3-superm1@kernel.org Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- drivers/platform/x86/amd/pmf/tee-if.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c index e008ac079fad..d3bd12ad036a 100644 --- a/drivers/platform/x86/amd/pmf/tee-if.c +++ b/drivers/platform/x86/amd/pmf/tee-if.c @@ -334,6 +334,11 @@ static int amd_pmf_start_policy_engine(struct amd_pmf_dev *dev) return 0; } +static inline bool amd_pmf_pb_valid(struct amd_pmf_dev *dev) +{ + return memchr_inv(dev->policy_buf, 0xff, dev->policy_sz); +} + #ifdef CONFIG_AMD_PMF_DEBUG static void amd_pmf_hex_dump_pb(struct amd_pmf_dev *dev) { @@ -361,6 +366,11 @@ static ssize_t amd_pmf_get_pb_data(struct file *filp, const char __user *buf, dev->policy_buf = new_policy_buf; dev->policy_sz = length; + if (!amd_pmf_pb_valid(dev)) { + ret = -EINVAL; + goto cleanup; + } + amd_pmf_hex_dump_pb(dev); ret = amd_pmf_start_policy_engine(dev); if (ret < 0) @@ -533,6 +543,12 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) memcpy_fromio(dev->policy_buf, dev->policy_base, dev->policy_sz); + if (!amd_pmf_pb_valid(dev)) { + dev_info(dev->dev, "No Smart PC policy present\n"); + ret = -EINVAL; + goto err_free_policy; + } + amd_pmf_hex_dump_pb(dev); dev->prev_data = kzalloc(sizeof(*dev->prev_data), GFP_KERNEL); -- 2.25.1