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)") Cc: stable@vger.kernel.org Co-developed-by: Natalia Petrova n.petrova@fintech.ru Signed-off-by: Nikita Zhandarovich n.zhandarovich@fintech.ru --- v2: free only resouces allocated prior, do not remove ci_dpm_fini() or other deallocating calls altogether; fix commit message. v1: https://lore.kernel.org/all/20230403182808.8699-1-n.zhandarovich@fintech.ru/
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 8ef25ab305ae..b8f4dac68d85 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; }