| Message ID | 20190629133114.14271-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/amdkfd: fix potential null pointer dereference on pointer peer_dev | expand |
From the comments , "we will loop GPUs that already be processed (with lower value of proximity_domain) ", the device should already been added into the topology_device_list. So in this case , kfd_topology_device_by_proximity_domain will not return a NULL pointer. If you really get the null pointer dereferences here , we must have some bigger problem and can not solved by added the null check here. Regards shaoyun.liu On 2019-06-29 9:31 a.m., Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > The call to kfd_topology_device_by_proximity_domain can return a NULL > pointer so add a null pointer check on peer_dev to the existing null > pointer check on peer_dev->gpu to avoid any potential null pointer > dereferences. > > Addresses-Coverity: ("Dereference on null return value") > Fixes: ae9a25aea7f3 ("drm/amdkfd: Generate xGMI direct iolink") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c > index 4e3fc284f6ac..cb6b46cfa6c2 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c > @@ -1293,7 +1293,7 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image, > if (kdev->hive_id) { > for (nid = 0; nid < proximity_domain; ++nid) { > peer_dev = kfd_topology_device_by_proximity_domain(nid); > - if (!peer_dev->gpu) > + if (!peer_dev || !peer_dev->gpu) > continue; > if (peer_dev->gpu->hive_id != kdev->hive_id) > continue;
I think this could happen if KFD initialization fails for a device. Currently we'd add the device, and then remove it again. That may leave a gap in the proximity domains. Oak just had a fix recently to clean that up by only adding KFD devices to the topology after successful initialization. Regards, Felix On 2019-07-02 11:29 a.m., Liu, Shaoyun wrote: > From the comments , "we will loop GPUs that already be processed (with > lower value of proximity_domain) ", the device should already been > added into the topology_device_list. So in this case , > kfd_topology_device_by_proximity_domain will not return a NULL pointer. > If you really get the null pointer dereferences here , we must have > some bigger problem and can not solved by added the null check here. > > Regards > > shaoyun.liu > > On 2019-06-29 9:31 a.m., Colin King wrote: >> From: Colin Ian King <colin.king@canonical.com> >> >> The call to kfd_topology_device_by_proximity_domain can return a NULL >> pointer so add a null pointer check on peer_dev to the existing null >> pointer check on peer_dev->gpu to avoid any potential null pointer >> dereferences. >> >> Addresses-Coverity: ("Dereference on null return value") >> Fixes: ae9a25aea7f3 ("drm/amdkfd: Generate xGMI direct iolink") >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> --- >> drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c >> index 4e3fc284f6ac..cb6b46cfa6c2 100644 >> --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c >> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c >> @@ -1293,7 +1293,7 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image, >> if (kdev->hive_id) { >> for (nid = 0; nid < proximity_domain; ++nid) { >> peer_dev = kfd_topology_device_by_proximity_domain(nid); >> - if (!peer_dev->gpu) >> + if (!peer_dev || !peer_dev->gpu) >> continue; >> if (peer_dev->gpu->hive_id != kdev->hive_id) >> continue; > _______________________________________________ > amd-gfx mailing list > amd-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c index 4e3fc284f6ac..cb6b46cfa6c2 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c @@ -1293,7 +1293,7 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image, if (kdev->hive_id) { for (nid = 0; nid < proximity_domain; ++nid) { peer_dev = kfd_topology_device_by_proximity_domain(nid); - if (!peer_dev->gpu) + if (!peer_dev || !peer_dev->gpu) continue; if (peer_dev->gpu->hive_id != kdev->hive_id) continue;