media: venus: Fix OPP table error handling

The venus driver fails to check if dev_pm_opp_find_freq_{ceil,floor}()
returns an error pointer before calling dev_pm_opp_put(). This causes
a crash when OPP tables are not present in device tree.

Unable to handle kernel access to user memory outside uaccess routines
at virtual address 000000000000002e
...
pc : dev_pm_opp_put+0x1c/0x4c
lr : core_clks_enable+0x4c/0x16c [venus_core]

Add IS_ERR() checks before calling dev_pm_opp_put() to avoid
dereferencing error pointers.

Fixes: b179234b5e59 ("media: venus: pm_helpers: use opp-table for the frequency")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/media/platform/qcom/venus/pm_helpers.c b/drivers/media/platform/qcom/venus/pm_helpers.c
index 8dd5a9b0d060cddfeafd4da477ade0c7aeb6c390..e32f8862a9f90c2fc3773fa3b25366c0f9c75790 100644 (file)
--- a/drivers/media/platform/qcom/venus/pm_helpers.c
+++ b/drivers/media/platform/qcom/venus/pm_helpers.c
@@ -48,7 +48,8 @@ static int core_clks_enable(struct venus_core *core)
        int ret;
 
        opp = dev_pm_opp_find_freq_ceil(dev, &freq);
-       dev_pm_opp_put(opp);
+       if (!IS_ERR(opp))
+               dev_pm_opp_put(opp);
 
        for (i = 0; i < res->clks_num; i++) {
                if (IS_V6(core)) {
@@ -660,7 +661,8 @@ static int decide_core(struct venus_inst *inst)
        /*TODO : divide this inst->load by work_route */
 
        opp = dev_pm_opp_find_freq_floor(dev, &max_freq);
-       dev_pm_opp_put(opp);
+       if (!IS_ERR(opp))
+               dev_pm_opp_put(opp);
 
        min_loaded_core(inst, &min_coreid, &min_load, false);
        min_loaded_core(inst, &min_lp_coreid, &min_lp_load, true);
@@ -1121,7 +1123,8 @@ static int load_scale_v4(struct venus_inst *inst)
        freq = max(freq_core1, freq_core2);
 
        opp = dev_pm_opp_find_freq_floor(dev, &max_freq);
-       dev_pm_opp_put(opp);
+       if (!IS_ERR(opp))
+               dev_pm_opp_put(opp);
 
        if (freq > max_freq) {
                dev_dbg(dev, VDBGL "requested clock rate: %lu scaling clock rate : %lu\n",
@@ -1131,7 +1134,8 @@ static int load_scale_v4(struct venus_inst *inst)
        }
 
        opp = dev_pm_opp_find_freq_ceil(dev, &freq);
-       dev_pm_opp_put(opp);
+       if (!IS_ERR(opp))
+               dev_pm_opp_put(opp);
 
 set_freq: