Just for patchwork's sake, since the tags got stuck below the --- Reviewed-by: Lyude Paul <[email protected]>
On Fri, 2026-10-09 at 11:44 -0600, Jim Cromie via B4 Relay wrote: > From: Jim Cromie <[email protected]> > > When graphics engine firmware fails to load or initialization aborts > early, nvxx_gr(drm) returns NULL. Calling > DRM_IOCTL_NOUVEAU_GET_ZCULL_INFO > causes nouveau_abi16_ioctl_get_zcull_info() to dereference gr at > offset > 0xf0 without checking for NULL, triggering a kernel page fault. > > Validate that gr is non-NULL before inspecting gr->has_zcull_info. > > Signed-off-by: Jim Cromie <[email protected]> > --- > Aug 14 09:21:52 frodo kernel: BUG: kernel NULL pointer dereference, > address: 00000000000000f0 > Aug 14 09:21:52 frodo kernel: #PF: error_code(0x0000) - not-present > page > Aug 14 09:21:52 frodo kernel: Oops: Oops: 0000 [#1] SMP NOPTI > Aug 14 09:21:52 frodo kernel: RIP: > 0010:nouveau_abi16_ioctl_get_zcull_info+0x17/0xa0 [nouveau] > Aug 14 09:21:52 frodo kernel: Code: 00 00 00 90 90 90 90 90 90 90 90 > 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 47 40 48 8b > 00 48 8b 80 70 02 00 00 <80> b8 f0 00 00 00 00 74 72 8b 90 c0 00 00 > 00 89 16 8b 90 c4 00 00 > Aug 14 09:21:52 frodo kernel: Call Trace: > Aug 14 09:21:52 frodo kernel: <TASK> > Aug 14 09:21:52 frodo kernel: drm_ioctl_kernel+0xae/0x100 > Aug 14 09:21:52 frodo kernel: drm_ioctl+0x2e0/0x560 > Aug 14 09:21:52 frodo kernel: ? > __pfx_nouveau_abi16_ioctl_get_zcull_info+0x10/0x10 [nouveau] > Aug 14 09:21:52 frodo kernel: nouveau_drm_ioctl+0x58/0xc0 [nouveau] > Aug 14 09:21:52 frodo kernel: __x64_sys_ioctl+0xb9/0x100 > Aug 14 09:21:52 frodo kernel: do_syscall_64+0xe2/0x560 > Aug 14 09:21:52 frodo kernel: > entry_SYSCALL_64_after_hwframe+0x76/0x7e > Aug 14 09:21:52 frodo kernel: </TASK> > > Reviewed-by: Lyude Paul <[email protected]> > Tested-by: Daniel Campos Ramos <[email protected]> > --- > drivers/gpu/drm/nouveau/nouveau_abi16.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_abi16.c > b/drivers/gpu/drm/nouveau/nouveau_abi16.c > index 3f130cd4fbcd..c7ddc54a3c4d 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_abi16.c > +++ b/drivers/gpu/drm/nouveau/nouveau_abi16.c > @@ -358,7 +358,7 @@ > nouveau_abi16_ioctl_get_zcull_info(ABI16_IOCTL_ARGS) > struct nvkm_gr *gr = nvxx_gr(drm); > struct drm_nouveau_get_zcull_info *out = data; > > - if (gr->has_zcull_info) { > + if (gr && gr->has_zcull_info) { > const struct nvkm_gr_zcull_info *i = &gr- > >zcull_info; > > out->width_align_pixels = i->width_align_pixels;
