From: Mario Limonciello Date: Thu, 22 May 2025 00:34:55 +0000 (-0500) Subject: platform/x86/amd: pmf: Use device managed allocations X-Git-Tag: v6.16-rc3~39^2~12 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d9db3a941270d92bbd1a6a6b54a10324484f2f2d;p=thirdparty%2Fkernel%2Flinux.git platform/x86/amd: pmf: Use device managed allocations If setting up smart PC fails for any reason then this can lead to a double free when unloading amd-pmf. This is because dev->buf was freed but never set to NULL and is again freed in amd_pmf_remove(). To avoid subtle allocation bugs in failures leading to a double free change all allocations into device managed allocations. Fixes: 5b1122fc4995f ("platform/x86/amd/pmf: fix cleanup in amd_pmf_init_smart_pc()") Link: https://lore.kernel.org/r/20250512211154.2510397-2-superm1@kernel.org Signed-off-by: Mario Limonciello Link: https://lore.kernel.org/r/20250522003457.1516679-2-superm1@kernel.org Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c index 76910601cac8..ef988605c4da 100644 --- a/drivers/platform/x86/amd/pmf/core.c +++ b/drivers/platform/x86/amd/pmf/core.c @@ -280,7 +280,7 @@ int amd_pmf_set_dram_addr(struct amd_pmf_dev *dev, bool alloc_buffer) dev_err(dev->dev, "Invalid CPU id: 0x%x", dev->cpu_id); } - dev->buf = kzalloc(dev->mtable_size, GFP_KERNEL); + dev->buf = devm_kzalloc(dev->dev, dev->mtable_size, GFP_KERNEL); if (!dev->buf) return -ENOMEM; } @@ -493,7 +493,6 @@ static void amd_pmf_remove(struct platform_device *pdev) mutex_destroy(&dev->lock); mutex_destroy(&dev->update_mutex); mutex_destroy(&dev->cb_mutex); - kfree(dev->buf); } static const struct attribute_group *amd_pmf_driver_groups[] = { diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c index d3bd12ad036a..027e992b7147 100644 --- a/drivers/platform/x86/amd/pmf/tee-if.c +++ b/drivers/platform/x86/amd/pmf/tee-if.c @@ -358,30 +358,28 @@ static ssize_t amd_pmf_get_pb_data(struct file *filp, const char __user *buf, return -EINVAL; /* re-alloc to the new buffer length of the policy binary */ - new_policy_buf = memdup_user(buf, length); - if (IS_ERR(new_policy_buf)) - return PTR_ERR(new_policy_buf); + new_policy_buf = devm_kzalloc(dev->dev, length, GFP_KERNEL); + if (!new_policy_buf) + return -ENOMEM; + + if (copy_from_user(new_policy_buf, buf, length)) { + devm_kfree(dev->dev, new_policy_buf); + return -EFAULT; + } - kfree(dev->policy_buf); + devm_kfree(dev->dev, dev->policy_buf); dev->policy_buf = new_policy_buf; dev->policy_sz = length; - if (!amd_pmf_pb_valid(dev)) { - ret = -EINVAL; - goto cleanup; - } + if (!amd_pmf_pb_valid(dev)) + return -EINVAL; amd_pmf_hex_dump_pb(dev); ret = amd_pmf_start_policy_engine(dev); if (ret < 0) - goto cleanup; + return ret; return length; - -cleanup: - kfree(dev->policy_buf); - dev->policy_buf = NULL; - return ret; } static const struct file_operations pb_fops = { @@ -532,13 +530,13 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) dev->policy_base = devm_ioremap_resource(dev->dev, dev->res); if (IS_ERR(dev->policy_base)) { ret = PTR_ERR(dev->policy_base); - goto err_free_dram_buf; + goto err_cancel_work; } - dev->policy_buf = kzalloc(dev->policy_sz, GFP_KERNEL); + dev->policy_buf = devm_kzalloc(dev->dev, dev->policy_sz, GFP_KERNEL); if (!dev->policy_buf) { ret = -ENOMEM; - goto err_free_dram_buf; + goto err_cancel_work; } memcpy_fromio(dev->policy_buf, dev->policy_base, dev->policy_sz); @@ -546,21 +544,21 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) if (!amd_pmf_pb_valid(dev)) { dev_info(dev->dev, "No Smart PC policy present\n"); ret = -EINVAL; - goto err_free_policy; + goto err_cancel_work; } amd_pmf_hex_dump_pb(dev); - dev->prev_data = kzalloc(sizeof(*dev->prev_data), GFP_KERNEL); + dev->prev_data = devm_kzalloc(dev->dev, sizeof(*dev->prev_data), GFP_KERNEL); if (!dev->prev_data) { ret = -ENOMEM; - goto err_free_policy; + goto err_cancel_work; } for (i = 0; i < ARRAY_SIZE(amd_pmf_ta_uuid); i++) { ret = amd_pmf_tee_init(dev, &amd_pmf_ta_uuid[i]); if (ret) - goto err_free_prev_data; + goto err_cancel_work; ret = amd_pmf_start_policy_engine(dev); switch (ret) { @@ -575,7 +573,7 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) default: ret = -EINVAL; amd_pmf_tee_deinit(dev); - goto err_free_prev_data; + goto err_cancel_work; } if (status) @@ -584,7 +582,7 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) if (!status && !pb_side_load) { ret = -EINVAL; - goto err_free_prev_data; + goto err_cancel_work; } if (pb_side_load) @@ -600,12 +598,6 @@ err_pmf_remove_pb: if (pb_side_load && dev->esbin) amd_pmf_remove_pb(dev); amd_pmf_tee_deinit(dev); -err_free_prev_data: - kfree(dev->prev_data); -err_free_policy: - kfree(dev->policy_buf); -err_free_dram_buf: - kfree(dev->buf); err_cancel_work: cancel_delayed_work_sync(&dev->pb_work); @@ -621,11 +613,5 @@ void amd_pmf_deinit_smart_pc(struct amd_pmf_dev *dev) amd_pmf_remove_pb(dev); cancel_delayed_work_sync(&dev->pb_work); - kfree(dev->prev_data); - dev->prev_data = NULL; - kfree(dev->policy_buf); - dev->policy_buf = NULL; - kfree(dev->buf); - dev->buf = NULL; amd_pmf_tee_deinit(dev); }