drm/amdkfd: guard against NULL restore_mqd in CRIU queue restore

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: guard against NULL restore_mqd in CRIU queue restore Both create_queue_cpsch() and create_queue_nocpsch() unconditionally call mqd_mgr->restore_mqd() when a CRIU restore is in progress (qd != NULL), with no NULL guard. On any system where restore_mqd is not implemented for the given queue type, a user holding CAP_CHECKPOINT_RESTORE can trigger a kernel NULL pointer dereference and panic the machine by issuing KFD_IOC_CRIU_OP_RESTORE with a crafted queue restore object. Note that checkpoint_mqd is likewise unimplemented on GFX12, so no legitimate CRIU image can reach this path — only a hand-crafted restore payload. Add a NULL guard for restore_mqd immediately after mqd_mgr is resolved, unwinding via the existing error labels and returning -EOPNOTSUPP if the callback is not implemented. This mirrors the existing checkpoint_mqd guard in checkpoint_mqd().

Timeline

1. Sep 16, 2026, 10:30 AM UTCCVE published
2. Oct 19, 2026, 8:53 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 48f0bdf4e38e42b8285622cfcfc7e6e490b1a719 · fixed in 19c73848493ab58e39649700da6de11710a36de1; From 48f0bdf4e38e42b8285622cfcfc7e6e490b1a719 · fixed in ebffa44e7a21ead59ac4b4264e8fc2cbb44c4a21; From 48f0bdf4e38e42b8285622cfcfc7e6e490b1a719 · fixed in c643c229babe2e8efc5eefe60e19d44868a643ff; From 48f0bdf4e38e42b8285622cfcfc7e6e490b1a719 · fixed in 6aa530642f95d5c48aa336416f94a35e7949b647

• Linux Linux

  6.11

• KernelLinux

  From 6.11.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5

References 4