Patch "radeon: avoid double free in ci_dpm_init()" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    radeon: avoid double free in ci_dpm_init()

to the 5.4-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:
     radeon-avoid-double-free-in-ci_dpm_init.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e2c127f46914a54e4105b6f582029ebd80336dac
Author: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
Date:   Thu Apr 13 08:12:28 2023 -0700

    radeon: avoid double free in ci_dpm_init()
    
    [ Upstream commit 20c3dffdccbd494e0dd631d1660aeecbff6775f2 ]
    
    Several calls to ci_dpm_fini() will attempt to free resources that
    either have been freed before or haven't been allocated yet. This
    may lead to undefined or dangerous behaviour.
    
    For instance, if r600_parse_extended_power_table() fails, it might
    call r600_free_extended_power_table() as will ci_dpm_fini() later
    during error handling.
    
    Fix this by only freeing pointers to objects previously allocated.
    
    Found by Linux Verification Center (linuxtesting.org) with static
    analysis tool SVACE.
    
    Fixes: cc8dbbb4f62a ("drm/radeon: add dpm support for CI dGPUs (v2)")
    Co-developed-by: Natalia Petrova <n.petrova@xxxxxxxxxx>
    Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
    Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/radeon/ci_dpm.c b/drivers/gpu/drm/radeon/ci_dpm.c
index 1e62e7bbf1b1d..5403f4c902b64 100644
--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -5556,6 +5556,7 @@ static int ci_parse_power_table(struct radeon_device *rdev)
 	u8 frev, crev;
 	u8 *power_state_offset;
 	struct ci_ps *ps;
+	int ret;
 
 	if (!atom_parse_data_header(mode_info->atom_context, index, NULL,
 				   &frev, &crev, &data_offset))
@@ -5585,11 +5586,15 @@ static int ci_parse_power_table(struct radeon_device *rdev)
 		non_clock_array_index = power_state->v2.nonClockInfoIndex;
 		non_clock_info = (struct _ATOM_PPLIB_NONCLOCK_INFO *)
 			&non_clock_info_array->nonClockInfo[non_clock_array_index];
-		if (!rdev->pm.power_state[i].clock_info)
-			return -EINVAL;
+		if (!rdev->pm.power_state[i].clock_info) {
+			ret = -EINVAL;
+			goto err_free_ps;
+		}
 		ps = kzalloc(sizeof(struct ci_ps), GFP_KERNEL);
-		if (ps == NULL)
-			return -ENOMEM;
+		if (ps == NULL) {
+			ret = -ENOMEM;
+			goto err_free_ps;
+		}
 		rdev->pm.dpm.ps[i].ps_priv = ps;
 		ci_parse_pplib_non_clock_info(rdev, &rdev->pm.dpm.ps[i],
 					      non_clock_info,
@@ -5629,6 +5634,12 @@ static int ci_parse_power_table(struct radeon_device *rdev)
 	}
 
 	return 0;
+
+err_free_ps:
+	for (i = 0; i < rdev->pm.dpm.num_ps; i++)
+		kfree(rdev->pm.dpm.ps[i].ps_priv);
+	kfree(rdev->pm.dpm.ps);
+	return ret;
 }
 
 static int ci_get_vbios_boot_values(struct radeon_device *rdev,
@@ -5717,25 +5728,26 @@ int ci_dpm_init(struct radeon_device *rdev)
 
 	ret = ci_get_vbios_boot_values(rdev, &pi->vbios_boot_state);
 	if (ret) {
-		ci_dpm_fini(rdev);
+		kfree(rdev->pm.dpm.priv);
 		return ret;
 	}
 
 	ret = r600_get_platform_caps(rdev);
 	if (ret) {
-		ci_dpm_fini(rdev);
+		kfree(rdev->pm.dpm.priv);
 		return ret;
 	}
 
 	ret = r600_parse_extended_power_table(rdev);
 	if (ret) {
-		ci_dpm_fini(rdev);
+		kfree(rdev->pm.dpm.priv);
 		return ret;
 	}
 
 	ret = ci_parse_power_table(rdev);
 	if (ret) {
-		ci_dpm_fini(rdev);
+		kfree(rdev->pm.dpm.priv);
+		r600_free_extended_power_table(rdev);
 		return ret;
 	}