drm/amdkfd: Fix OOB memory exposure in get_wave_state()

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix OOB memory exposure in get_wave_state() The get_wave_state() function for v9 trusts cp_hqd_cntl_stack_size and cp_hqd_cntl_stack_offset values read directly from the MQD, which are written by GPU microcode and fully attacker-controlled on the CRIU-restore path (via AMDKFD_IOC_RESTORE_PROCESS with H3). this leads to an unbounded copy_to_user() that can leak adjacent GTT/kernel memory. If offset > size, integer underflow produces a ~4 GiB read length, if size is set to 1 MiB against a 4 KiB allocation, we leak 1 MiB of adjacent kernel memory (other queues' MQDs, ring buffers, KASLR pointers). Fix by clamping both cp_hqd_cntl_stack_size to the actual allocated buffer size (q->ctl_stack_size) and cp_hqd_cntl_stack_offset to the clamped size before performing arithmetic and copy_to_user(). This ensures we never read beyond the allocated kernel BO regardless of attacker-supplied MQD field values.

Timeline

1. Sep 24, 2026, 4:04 PM UTCCVE published
2. Oct 3, 2026, 10:58 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 42c6c48214b726c30918e8dc80e2168607d13ae4 · fixed in e2bef0f168be46692a6b900916ff5da3771480ed; From 42c6c48214b726c30918e8dc80e2168607d13ae4 · fixed in d9183d974ddd5f09d029beaf359275ac20d4d5fe; From 42c6c48214b726c30918e8dc80e2168607d13ae4 · fixed in ec646686613d8ab05b282d1463a7baa49fd6b83b; From 42c6c48214b726c30918e8dc80e2168607d13ae4 · fixed in 7ef144458f48d5589e36f1b3d83e83db2e5c5ba5

• Linux Linux

  5.18

• KernelLinux

  From 5.18.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53

References 4