Revert "drm/amdgpu: fix slab-use-after-free in amdgpu_userq_mgr_fini"

[ Upstream commit a73345b866ff8bbd93135af667c973a8fb4b2c40 ]

This reverts commit 5fb90421fa0fbe0a968274912101fe917bf1c47b.

The original patch moved `amdgpu_userq_mgr_fini()` to the driver's
`postclose` callback, which is called after `drm_gem_release()` in
the DRM file cleanup sequence.If a user application crashes or aborts
without cleaning up its user queues, 'drm_gem_release()` may free
GEM objects that are still referenced by active user queues, leading
to use-after-free. By reverting, we ensure that user queues are
disabled and cleaned up before any GEM objects are released,
preventing this class of bug. However, this reintroduces a race
during PCI hot-unplug, where device removal can race with per-file
cleanup, leading to use-after-free in suspend/unplug paths.
This will be fixed in the next patch.

Fixes: 5fb90421fa0f ("drm/amdgpu: fix slab-use-after-free in amdgpu_userq_mgr_fini+0x70c")
Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 501bb82f2a37354e666d8447a71b454df918eb8d..4db92e0a60da7b37ad0be30fbc4c6f0d30836153 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -2906,6 +2906,20 @@ done:
        return ret;
 }
 
+static int amdgpu_drm_release(struct inode *inode, struct file *filp)
+{
+       struct drm_file *file_priv = filp->private_data;
+       struct amdgpu_fpriv *fpriv = file_priv->driver_priv;
+
+       if (fpriv) {
+               fpriv->evf_mgr.fd_closing = true;
+               amdgpu_eviction_fence_destroy(&fpriv->evf_mgr);
+               amdgpu_userq_mgr_fini(&fpriv->userq_mgr);
+       }
+
+       return drm_release(inode, filp);
+}
+
 long amdgpu_drm_ioctl(struct file *filp,
                      unsigned int cmd, unsigned long arg)
 {
@@ -2957,7 +2971,7 @@ static const struct file_operations amdgpu_driver_kms_fops = {
        .owner = THIS_MODULE,
        .open = drm_open,
        .flush = amdgpu_flush,
-       .release = drm_release,
+       .release = amdgpu_drm_release,
        .unlocked_ioctl = amdgpu_drm_ioctl,
        .mmap = drm_gem_mmap,
        .poll = drm_poll,

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 195ed81d39ffe3df2713291775320794162e9c93..d2ce7d86dbc8e9ce97f5125e14095cfebced4b7f 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -1501,9 +1501,6 @@ void amdgpu_driver_postclose_kms(struct drm_device *dev,
                amdgpu_vm_bo_del(adev, fpriv->prt_va);
                amdgpu_bo_unreserve(pd);
        }
-       fpriv->evf_mgr.fd_closing = true;
-       amdgpu_eviction_fence_destroy(&fpriv->evf_mgr);
-       amdgpu_userq_mgr_fini(&fpriv->userq_mgr);
 
        amdgpu_ctx_mgr_fini(&fpriv->ctx_mgr);
        amdgpu_vm_fini(adev, &fpriv->vm);