Avoid leaving a hanging pre-allocated clock_info if last mode is invalid, and avoid heap corruption if no valid modes are found.
Fixes: 6991b8f2a319 ("drm/radeon/kms: fix segfault in pm rework") Signed-off-by: Kees Cook keescook@chromium.org --- drivers/gpu/drm/radeon/radeon_atombios.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c index f9f4efa1738c..28c4413f4dc8 100644 --- a/drivers/gpu/drm/radeon/radeon_atombios.c +++ b/drivers/gpu/drm/radeon/radeon_atombios.c @@ -2120,11 +2120,14 @@ static int radeon_atombios_parse_power_table_1_3(struct radeon_device *rdev) return state_index; /* last mode is usually default, array is low to high */ for (i = 0; i < num_modes; i++) { - rdev->pm.power_state[state_index].clock_info = - kcalloc(1, sizeof(struct radeon_pm_clock_info), - GFP_KERNEL); + /* avoid memory leaks from invalid modes or unknown frev. */ + if (!rdev->pm.power_state[state_index].clock_info) { + rdev->pm.power_state[state_index].clock_info = + kzalloc(sizeof(struct radeon_pm_clock_info), + GFP_KERNEL); + } if (!rdev->pm.power_state[state_index].clock_info) - return state_index; + goto out; rdev->pm.power_state[state_index].num_clock_modes = 1; rdev->pm.power_state[state_index].clock_info[0].voltage.type = VOLTAGE_NONE; switch (frev) { @@ -2243,8 +2246,15 @@ static int radeon_atombios_parse_power_table_1_3(struct radeon_device *rdev) break; } } +out: + /* free any unused clock_info allocation. */ + if (state_index && state_index < num_modes) { + kfree(rdev->pm.power_state[state_index].clock_info); + rdev->pm.power_state[state_index].clock_info = NULL; + } + /* last mode is usually default */ - if (rdev->pm.default_power_state_index == -1) { + if (state_index && rdev->pm.default_power_state_index == -1) { rdev->pm.power_state[state_index - 1].type = POWER_STATE_TYPE_DEFAULT; rdev->pm.default_power_state_index = state_index - 1;