[PATCH 6.4 226/800] radeon: avoid double free in ci_dpm_init()

Greg Kroah-Hartman
2023-07-16T20:03:24Z

From: Nikita Zhandarovich <n.zhandarovich@fintech.ru>

[ 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@fintech.ru>
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/radeon/ci_dpm.c | 28 ++++++++++++++++++++--------
1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/radeon/ci_dpm.c b/drivers/gpu/drm/radeon/ci_dpm.c
index 8ef25ab305ae7..b8f4dac68d850 100644
--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -5517,6 +5517,7 @@ 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))
@@ -5546,11 +5547,15 @@ 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,
@@ -5590,6 +5595,12 @@ 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,
@@ -5678,25 +5689,26 @@ 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;
}

--
2.39.2