CVE-2026-74447: drm/amdkfd: fix uint32_t overflow in EOP ring buffer size alignment

From: Greg Kroah-Hartman <[email protected]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

drm/amdkfd: fix uint32_t overflow in EOP ring buffer size alignment

eop_ring_buffer_size in struct queue_properties is a u32. In
kfd_queue_acquire_buffers() the expected EOP buffer size is computed as
ALIGN(eop_ring_buffer_size, PAGE_SIZE); ALIGN uses typeof(x), so the
addition is done in 32-bit. A user-supplied size of 0xFFFFF001 wraps to
0, causing kfd_queue_buffer_get() to skip its exact-size check (gated on
size != 0) and accept any BO mapped at the address. On GFX8/GFX9 the MQD
cp_hqd_eop_control is then programmed for an 8KB EOP ring backed by a 4KB
BO, so CP EOP writes can land past the buffer and fault the GPU.

Cast the operand to u64 so the alignment is computed in 64-bit; the size
check in kfd_queue_buffer_get() then rejects the oversized request.

(cherry picked from commit ae443117b742c357bfef3a7bddabf76fcf86e9ef)

The Linux kernel CVE team has assigned CVE-2026-74447 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.12.75 with commit ee0dc6c66a913260311876a4b2b53fe0b9bc3f94 and fixed in 6.12.103 with commit 273548eb997c6be85230c1236b18784b09f6203c
	Issue introduced in 6.18.16 with commit acfc84cfa70aca5b970faf152979bc97b9f8b0c0 and fixed in 6.18.44 with commit 6dc0b4b39ed4f11ef70f76ecea8537e35f45342b
	Issue introduced in 7.0 with commit 42ea9cf2f16b7131cb7302acb3dac510968f8bdc and fixed in 7.1.8 with commit 7c54bd225d83bc1bcb44430ed4b4d3a5c36b1961
	Issue introduced in 7.0 with commit 42ea9cf2f16b7131cb7302acb3dac510968f8bdc and fixed in 7.2-rc6 with commit 83463a96ea3c7d8ae636a4d6a0ba63c9ce410724
	Issue introduced in 6.19.6 with commit c6ce687077cc67e4f3cbd0c89cb356fbbce91f4c

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-74447
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/gpu/drm/amd/amdkfd/kfd_queue.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/273548eb997c6be85230c1236b18784b09f6203c
	https://git.kernel.org/stable/c/6dc0b4b39ed4f11ef70f76ecea8537e35f45342b
	https://git.kernel.org/stable/c/7c54bd225d83bc1bcb44430ed4b4d3a5c36b1961
	https://git.kernel.org/stable/c/83463a96ea3c7d8ae636a4d6a0ba63c9ce410724