Applied. Thanks! Alex On Wed, Dec 1, 2021 at 10:16 AM Christian König <christian.koenig@xxxxxxx> wrote: > > Am 01.12.21 um 16:13 schrieb Zhou Qingyang: > > In radeon_driver_open_kms(), radeon_vm_bo_add() is assigned to > > vm->ib_bo_va and passes and used in radeon_vm_bo_set_addr(). In > > radeon_vm_bo_set_addr(), there is a dereference of vm->ib_bo_va, > > which could lead to a NULL pointer dereference on failure of > > radeon_vm_bo_add(). > > > > Fix this bug by adding a check of vm->ib_bo_va. > > > > This bug was found by a static analyzer. The analysis employs > > differential checking to identify inconsistent security operations > > (e.g., checks or kfrees) between two code paths and confirms that the > > inconsistent operations are not recovered in the current function or > > the callers, so they constitute bugs. > > > > Note that, as a bug found by static analysis, it can be a false > > positive or hard to trigger. Multiple researchers have cross-reviewed > > the bug. > > > > Builds with CONFIG_DRM_RADEON=m show no new warnings, > > and our static analyzer no longer warns about this code. > > > > Fixes: cc9e67e3d700 ("drm/radeon: fix VM IB handling") > > Signed-off-by: Zhou Qingyang <zhou1615@xxxxxxx> > > --- > > Changes in v5: > > - Use conditions to avoid unnecessary initialization > > > > Changes in v4: > > - Initialize the variables to silence warning > > > > Changes in v3: > > - Fix the bug that good case will also be freed > > - Improve code style > > > > Changes in v2: > > - Improve the error handling into goto style > > > > drivers/gpu/drm/radeon/radeon_kms.c | 36 ++++++++++++++++------------- > > 1 file changed, 20 insertions(+), 16 deletions(-) > > > > diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c > > index 482fb0ae6cb5..66aee48fd09d 100644 > > --- a/drivers/gpu/drm/radeon/radeon_kms.c > > +++ b/drivers/gpu/drm/radeon/radeon_kms.c > > @@ -648,6 +648,8 @@ void radeon_driver_lastclose_kms(struct drm_device *dev) > > int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv) > > { > > struct radeon_device *rdev = dev->dev_private; > > + struct radeon_fpriv *fpriv; > > + struct radeon_vm *vm; > > int r; > > > > file_priv->driver_priv = NULL; > > @@ -660,8 +662,6 @@ int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv) > > > > /* new gpu have virtual address space support */ > > if (rdev->family >= CHIP_CAYMAN) { > > - struct radeon_fpriv *fpriv; > > - struct radeon_vm *vm; > > > > fpriv = kzalloc(sizeof(*fpriv), GFP_KERNEL); > > if (unlikely(!fpriv)) { > > @@ -672,35 +672,39 @@ int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv) > > if (rdev->accel_working) { > > vm = &fpriv->vm; > > r = radeon_vm_init(rdev, vm); > > - if (r) { > > - kfree(fpriv); > > - goto out_suspend; > > - } > > + if (r) > > + goto out_fpriv; > > > > r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false); > > - if (r) { > > - radeon_vm_fini(rdev, vm); > > - kfree(fpriv); > > - goto out_suspend; > > - } > > + if (r) > > + goto out_vm_fini; > > > > /* map the ib pool buffer read only into > > * virtual address space */ > > vm->ib_bo_va = radeon_vm_bo_add(rdev, vm, > > rdev->ring_tmp_bo.bo); > > + if (!vm->ib_bo_va) { > > + r = -ENOMEM; > > + goto out_vm_fini; > > + } > > + > > r = radeon_vm_bo_set_addr(rdev, vm->ib_bo_va, > > RADEON_VA_IB_OFFSET, > > RADEON_VM_PAGE_READABLE | > > RADEON_VM_PAGE_SNOOPED); > > - if (r) { > > - radeon_vm_fini(rdev, vm); > > - kfree(fpriv); > > - goto out_suspend; > > - } > > + if (r) > > + goto out_vm_fini; > > } > > file_priv->driver_priv = fpriv; > > } > > > > + if (!r) > > I think that test is unecessary now, maybe double check. > > Either way patch Reviewed-by: Christian König > <christian.koenig@xxxxxxx>. Alex will probably pick it up now. > > Thanks for the help, > Christian. > > > + goto out_suspend; > > + > > +out_vm_fini: > > + radeon_vm_fini(rdev, vm); > > +out_fpriv: > > + kfree(fpriv); > > out_suspend: > > pm_runtime_mark_last_busy(dev->dev); > > pm_runtime_put_autosuspend(dev->dev); >