CVE-2026-68105: drm/amdgpu: Fix kernel panic during driver load failure

CVE-2026-68105: drm/amdgpu: Fix kernel panic during driver load failure

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

drm/amdgpu: Fix kernel panic during driver load failure

Avoid kernel panic if MES init fails during driver load. The KIQ ring is
falsely marked as ready as ASICs that use MES, KIQ is owned by MES.

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:gfx_v12_1_wait_reg_mem+0x5a/0x1f0 [amdgpu]
Call Trace:
 gfx_v12_1_ring_emit_reg_write_reg_wait+0x1f/0x30 [amdgpu]
 amdgpu_gmc_fw_reg_write_reg_wait+0xb2/0x190 [amdgpu]
 amdgpu_gmc_flush_gpu_tlb+0x1cc/0x230 [amdgpu]
 amdgpu_gart_invalidate_tlb+0x81/0xa0 [amdgpu]
 amdgpu_gart_unbind+0x72/0x90 [amdgpu]
 amdgpu_ttm_backend_unbind+0xa4/0xb0 [amdgpu]
 amdgpu_ttm_tt_unpopulate+0x13/0xd0 [amdgpu]
 amdttm_tt_unpopulate+0x29/0x70 [amdttm]
 ttm_bo_put+0x1eb/0x360 [amdttm]
 amdgpu_bo_free_kernel+0xf9/0x1f0 [amdgpu]
 amdgpu_ih_ring_fini+0x5a/0x90 [amdgpu]
 amdgpu_irq_fini_hw+0x58/0x80 [amdgpu]
 amdgpu_device_fini_hw+0x4e0/0x5b0 [amdgpu]
 amdgpu_driver_load_kms+0x60/0xa0 [amdgpu]
 amdgpu_pci_probe+0x28e/0x6d0 [amdgpu]
 pci_device_probe+0x19f/0x220
 really_probe+0x1ed/0x340
 driver_probe_device+0x1e/0x80
 __driver_attach+0xd3/0x1a0
 bus_for_each_dev+0x68/0xa0
 bus_add_driver+0x19f/0x270
 driver_register+0x5d/0xf0
 do_one_initcall+0xac/0x200
 do_init_module+0x1ec/0x280
 __se_sys_finit_module+0x2de/0x310
 do_syscall_64+0x6a/0x250
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

(cherry picked from commit 4623b958dd6da0f4c3026afdf330626a09ecb0f0)

The Linux kernel CVE team has assigned CVE-2026-68105 to this issue.


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

	Fixed in 7.1.6 with commit 5bc93f907bad7e076d814664dfab8fc230efca3d
	Fixed in 7.2-rc2 with commit a279bd143b3c184358b658e43a057e31ee8c4de5

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-2026-68105
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/amdgpu/gfx_v12_0.c
	drivers/gpu/drm/amd/amdgpu/gfx_v12_1.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/5bc93f907bad7e076d814664dfab8fc230efca3d
	https://git.kernel.org/stable/c/a279bd143b3c184358b658e43a057e31ee8c4de5