On Wed, Oct 9, 2024 at 2:35 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > On Wed, Oct 09, 2024 at 12:49:49PM -0600, Everest K.C. wrote: > > The pointer list->list was derefrenced before the Null check > > resulting in possibility of Null pointer derefrencing. > > This patch moves the Null check outside the for loop, so that > > the check is performed before the derefrencing. > > > > This issue was reported by Coverity Scan. > > > > Signed-off-by: Everest K.C. <everestkc@xxxxxxxxxxxxxxxx> > > You need to add a Fixes tag. Will add it and send a V2. > > --- > > drivers/gpu/drm/xe/xe_guc_capture.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/xe/xe_guc_capture.c b/drivers/gpu/drm/xe/xe_guc_capture.c > > index 41262bda20ed..de63c622747d 100644 > > --- a/drivers/gpu/drm/xe/xe_guc_capture.c > > +++ b/drivers/gpu/drm/xe/xe_guc_capture.c > > @@ -1537,13 +1537,13 @@ read_reg_to_node(struct xe_hw_engine *hwe, const struct __guc_mmio_reg_descr_gro > > if (!regs) > > return; > > > > + if (!list->list) > > + return; > > Could you merge this with the other sanity checks at the start of the function. > > - if (!list || list->num_regs == 0) > + if (!list || !list->list || list->num_regs == 0) That looks better. Will do that in V2 and send it. > The list->list pointer can't actually be NULL. It comes from > guc_capture_get_one_list(), so if the reglists[i].list pointer is NULL it > returns NULL. However, obviously checking for NULL after a dereference is not > the correct so it's worth fixing and probably deserves a Fixes tag. Although it > doesn't affect runtime, adding a Fixes tag helps backporters know they can > automatically ignore this one because the commit it's fixing is very recent. > > regards, > dan carpenter >
