CVE-2019-19067 (published 2019-11-18T06:15Z)

Four memory leaks in the acp_hw_init() function in drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c in the Linux kernel before 5.3.8 allow attackers to cause a denial of service (memory consumption) by triggering mfd_add_hotplug_devices() or pm_genpd_add_device() failures, aka CID-57be09c6e874. NOTE: third parties dispute the relevance of this because the attacker must already have privileges for module loading

Severity: MEDIUM
CVSS v2 base score: 4.9 (AV:L/AC:L/Au:N/C:N/I:N/A:C)
CVSS v3 base score: 4.4, MEDIUM (CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)

Weakness information:
cwe_id: CWE-401
cwe_name: Missing Release of Memory after Effective Lifetime
description: The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.
extended_description: This is often triggered by improper handling of malformed data or unexpectedly interrupted sessions.  In some languages, developers are responsible for tracking memory allocation and releasing the memory.  If there are no more pointers or references to the memory, then it can no longer be tracked and identified for release.
         

Fix information:
repo_url: https://github.com/torvalds/linux
commit_details: repo_url: https://github.com/torvalds/linux
author: Navid Emamdoost
author_date: 2019-10-01 22:46:07-05:00
msg: drm/amdgpu: fix multiple memory leaks in acp_hw_init

In acp_hw_init there are some allocations that needs to be released in
case of failure:

1- adev->acp.acp_genpd should be released if any allocation attemp for
adev->acp.acp_cell, adev->acp.acp_res or i2s_pdata fails.
2- all of those allocations should be released if
mfd_add_hotplug_devices or pm_genpd_add_device fail.
3- Release is needed in case of time out values expire.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
repository: repo_url: https://github.com/torvalds/linux
repo_name: torvalds/linux
description: Linux kernel source tree
repo_language: C
owner: torvalds
file_changes: filename: amdgpu_acp.c
change_type: ModificationType.MODIFY
diff: @@ -189,7 +189,7 @@ static int acp_hw_init(void *handle)
 	u32 val = 0;
 	u32 count = 0;
 	struct device *dev;
-	struct i2s_platform_data *i2s_pdata;
+	struct i2s_platform_data *i2s_pdata = NULL;
 
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
@@ -231,20 +231,21 @@ static int acp_hw_init(void *handle)
 	adev->acp.acp_cell = kcalloc(ACP_DEVS, sizeof(struct mfd_cell),
 							GFP_KERNEL);
 
-	if (adev->acp.acp_cell == NULL)
-		return -ENOMEM;
+	if (adev->acp.acp_cell == NULL) {
+		r = -ENOMEM;
+		goto failure;
+	}
 
 	adev->acp.acp_res = kcalloc(5, sizeof(struct resource), GFP_KERNEL);
 	if (adev->acp.acp_res == NULL) {
-		kfree(adev->acp.acp_cell);
-		return -ENOMEM;
+		r = -ENOMEM;
+		goto failure;
 	}
 
 	i2s_pdata = kcalloc(3, sizeof(struct i2s_platform_data), GFP_KERNEL);
 	if (i2s_pdata == NULL) {
-		kfree(adev->acp.acp_res);
-		kfree(adev->acp.acp_cell);
-		return -ENOMEM;
+		r = -ENOMEM;
+		goto failure;
 	}
 
 	switch (adev->asic_type) {
@@ -341,14 +342,14 @@ static int acp_hw_init(void *handle)
 	r = mfd_add_hotplug_devices(adev->acp.parent, adev->acp.acp_cell,
 								ACP_DEVS);
 	if (r)
-		return r;
+		goto failure;
 
 	for (i = 0; i < ACP_DEVS ; i++) {
 		dev = get_mfd_cell_dev(adev->acp.acp_cell[i].name, i);
 		r = pm_genpd_add_device(&adev->acp.acp_genpd->gpd, dev);
 		if (r) {
 			dev_err(dev, "Failed to add dev to genpd\n");
-			return r;
+			goto failure;
 		}
 	}
 
@@ -367,7 +368,8 @@ static int acp_hw_init(void *handle)
 			break;
 		if (--count == 0) {
 			dev_err(&adev->pdev->dev, "Failed to reset ACP\n");
-			return -ETIMEDOUT;
+			r = -ETIMEDOUT;
+			goto failure;
 		}
 		udelay(100);
 	}
@@ -384,7 +386,8 @@ static int acp_hw_init(void *handle)
 			break;
 		if (--count == 0) {
 			dev_err(&adev->pdev->dev, "Failed to reset ACP\n");
-			return -ETIMEDOUT;
+			r = -ETIMEDOUT;
+			goto failure;
 		}
 		udelay(100);
 	}
@@ -393,6 +396,13 @@ static int acp_hw_init(void *handle)
 	val &= ~ACP_SOFT_RESET__SoftResetAud_MASK;
 	cgs_write_register(adev->acp.cgs_device, mmACP_SOFT_RESET, val);
 	return 0;
+
+failure:
+	kfree(i2s_pdata);
+	kfree(adev->acp.acp_res);
+	kfree(adev->acp.acp_cell);
+	kfree(adev->acp.acp_genpd);
+	return r;
 }
 
 /**

programming_language: C