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Subject[PATCH 5.4 095/109] drm/radeon: fix double free
Date
From: Tom Rix <trix@redhat.com>

commit 41855a898650803e24b284173354cc3e44d07725 upstream.

clang static analysis flags this error

drivers/gpu/drm/radeon/ci_dpm.c:5652:9: warning: Use of memory after it is freed [unix.Malloc]
kfree(rdev->pm.dpm.ps[i].ps_priv);
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/radeon/ci_dpm.c:5654:2: warning: Attempt to free released memory [unix.Malloc]
kfree(rdev->pm.dpm.ps);
^~~~~~~~~~~~~~~~~~~~~~

problem is reported in ci_dpm_fini, with these code blocks.

for (i = 0; i < rdev->pm.dpm.num_ps; i++) {
kfree(rdev->pm.dpm.ps[i].ps_priv);
}
kfree(rdev->pm.dpm.ps);

The first free happens in ci_parse_power_table where it cleans up locally
on a failure. ci_dpm_fini also does a cleanup.

ret = ci_parse_power_table(rdev);
if (ret) {
ci_dpm_fini(rdev);
return ret;
}

So remove the cleanup in ci_parse_power_table and
move the num_ps calculation to inside the loop so ci_dpm_fini
will know how many array elements to free.

Fixes: cc8dbbb4f62a ("drm/radeon: add dpm support for CI dGPUs (v2)")

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/radeon/ci_dpm.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/radeon/ci_dpm.c
+++ b/drivers/gpu/drm/radeon/ci_dpm.c
@@ -5578,6 +5578,7 @@ static int ci_parse_power_table(struct r
if (!rdev->pm.dpm.ps)
return -ENOMEM;
power_state_offset = (u8 *)state_array->states;
+ rdev->pm.dpm.num_ps = 0;
for (i = 0; i < state_array->ucNumEntries; i++) {
u8 *idx;
power_state = (union pplib_power_state *)power_state_offset;
@@ -5587,10 +5588,8 @@ static int ci_parse_power_table(struct r
if (!rdev->pm.power_state[i].clock_info)
return -EINVAL;
ps = kzalloc(sizeof(struct ci_ps), GFP_KERNEL);
- if (ps == NULL) {
- kfree(rdev->pm.dpm.ps);
+ if (ps == NULL)
return -ENOMEM;
- }
rdev->pm.dpm.ps[i].ps_priv = ps;
ci_parse_pplib_non_clock_info(rdev, &rdev->pm.dpm.ps[i],
non_clock_info,
@@ -5612,8 +5611,8 @@ static int ci_parse_power_table(struct r
k++;
}
power_state_offset += 2 + power_state->v2.ucNumDPMLevels;
+ rdev->pm.dpm.num_ps = i + 1;
}
- rdev->pm.dpm.num_ps = state_array->ucNumEntries;

/* fill in the vce power states */
for (i = 0; i < RADEON_MAX_VCE_LEVELS; i++) {

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