[PATCH V4] drm/xe/guc: Fix dereference before NULL check
Everest K.C.
everestkc at everestkc.com.np
Thu Oct 10 16:57:59 UTC 2024
The pointer list->list is dereferenced before the NULL check.
Fix this by moving the NULL check outside the for loop, so that
the check is performed before the dereferencing.
The list->list pointer cannot be NULL so this has no effect on runtime.
It's just a correctness issue.
This issue was reported by Coverity Scan.
https://scan7.scan.coverity.com/#/project-view/51525/11354?selectedIssue=1600335
Fixes: 0f1fdf559225 ("drm/xe/guc: Save manual engine capture into capture list")
Signed-off-by: Everest K.C. <everestkc at everestkc.com.np>
Reviewed-by: Dan Carpenter <dan.carpenter at linaro.org>
---
V3 -> V4: - Corrected the Fixes tag
- Added Reviewed-by tag
V2 -> V3: - Changed Null to NULL in the changelog
- Corrected typo in the changelong
- Added more description to the changelong
- Fixed the link for Coverity Report
- Removed the space after the Fixes tag
V1 -> V2: - Combined the `!list->list` check in preexisting if statement
- Added Fixes tag
- Added the link to the Coverity Scan report
drivers/gpu/drm/xe/xe_guc_capture.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_guc_capture.c b/drivers/gpu/drm/xe/xe_guc_capture.c
index 41262bda20ed..947c3a6d0e5a 100644
--- a/drivers/gpu/drm/xe/xe_guc_capture.c
+++ b/drivers/gpu/drm/xe/xe_guc_capture.c
@@ -1531,7 +1531,7 @@ read_reg_to_node(struct xe_hw_engine *hwe, const struct __guc_mmio_reg_descr_gro
{
int i;
- if (!list || list->num_regs == 0)
+ if (!list || !list->list || list->num_regs == 0)
return;
if (!regs)
@@ -1541,9 +1541,6 @@ read_reg_to_node(struct xe_hw_engine *hwe, const struct __guc_mmio_reg_descr_gro
struct __guc_mmio_reg_descr desc = list->list[i];
u32 value;
- if (!list->list)
- return;
-
if (list->type == GUC_STATE_CAPTURE_TYPE_ENGINE_INSTANCE) {
value = xe_hw_engine_mmio_read32(hwe, desc.reg);
} else {
--
2.43.0
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