* [PATCH v5] drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms() [not found] <e2685075-fbc5-6f36-907f-76b6f76a59ce@amd.com> @ 2021-12-01 15:13 ` Zhou Qingyang 2021-12-01 15:15 ` Christian König 0 siblings, 1 reply; 3+ messages in thread From: Zhou Qingyang @ 2021-12-01 15:13 UTC (permalink / raw) To: zhou1615 Cc: kjlu, Alex Deucher, Christian König, Pan, Xinhui, David Airlie, Daniel Vetter, amd-gfx, dri-devel, linux-kernel 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@umn.edu> --- 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) + 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); -- 2.25.1 ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v5] drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms() 2021-12-01 15:13 ` [PATCH v5] drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms() Zhou Qingyang @ 2021-12-01 15:15 ` Christian König 2021-12-02 17:13 ` Alex Deucher 0 siblings, 1 reply; 3+ messages in thread From: Christian König @ 2021-12-01 15:15 UTC (permalink / raw) To: Zhou Qingyang Cc: kjlu, Alex Deucher, Pan, Xinhui, David Airlie, Daniel Vetter, amd-gfx, dri-devel, linux-kernel 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@umn.edu> > --- > 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@amd.com>. 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); ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v5] drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms() 2021-12-01 15:15 ` Christian König @ 2021-12-02 17:13 ` Alex Deucher 0 siblings, 0 replies; 3+ messages in thread From: Alex Deucher @ 2021-12-02 17:13 UTC (permalink / raw) To: Christian König Cc: Zhou Qingyang, David Airlie, Pan, Xinhui, Kangjie Lu, LKML, amd-gfx list, Maling list - DRI developers, Alex Deucher Applied. Thanks! Alex On Wed, Dec 1, 2021 at 10:16 AM Christian König <christian.koenig@amd.com> 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@umn.edu> > > --- > > 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@amd.com>. 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); > ^ permalink raw reply [flat|nested] 3+ messages in thread
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[not found] <e2685075-fbc5-6f36-907f-76b6f76a59ce@amd.com>
2021-12-01 15:13 ` [PATCH v5] drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms() Zhou Qingyang
2021-12-01 15:15 ` Christian König
2021-12-02 17:13 ` Alex Deucher
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