| Message ID | 20241010064636.3970-1-everestkc@everestkc.com.np (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V3] drm/xe/guc: Fix dereference before NULL check | expand |
On Thu, Oct 10, 2024 at 12:46:34AM -0600, Everest K.C. wrote: > 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: a18c696fa5cb ("drm/xe/guc: Fix dereference before Null check") > Signed-off-by: Everest K.C. <everestkc@everestkc.com.np> > --- Perfect! Thanks. Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> regards, dan carpenter
On 10.10.2024 08:54, Dan Carpenter wrote: > On Thu, Oct 10, 2024 at 12:46:34AM -0600, Everest K.C. wrote: >> 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: a18c696fa5cb ("drm/xe/guc: Fix dereference before Null check") hmm, this seems wrong, shouldn't this be: Fixes: 0f1fdf559225 ("drm/xe/guc: Save manual engine capture into capture list") >> Signed-off-by: Everest K.C. <everestkc@everestkc.com.np> >> --- > > Perfect! Thanks. > > Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> > > regards, > dan carpenter >
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 {
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: a18c696fa5cb ("drm/xe/guc: Fix dereference before Null check") Signed-off-by: Everest K.C. <everestkc@everestkc.com.np> --- 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(-)