Subject: CVE-2024-43899: drm/amd/display: Fix null pointer deref in dcn20_resource.c

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

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

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

drm/amd/display: Fix null pointer deref in dcn20_resource.c

Fixes a hang thats triggered when MPV is run on a DCN401 dGPU:

mpv --hwdec=vaapi --vo=gpu --hwdec-codecs=all

and then enabling fullscreen playback (double click on the video)

The following calltrace will be seen:

[  181.843989] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  181.843997] #PF: supervisor instruction fetch in kernel mode
[  181.844003] #PF: error_code(0x0010) - not-present page
[  181.844009] PGD 0 P4D 0
[  181.844020] Oops: 0010 [#1] PREEMPT SMP NOPTI
[  181.844028] CPU: 6 PID: 1892 Comm: gnome-shell Tainted: G        W  OE      6.5.0-41-generic #41~22.04.2-Ubuntu
[  181.844038] Hardware name: System manufacturer System Product Name/CROSSHAIR VI HERO, BIOS 6302 10/23/2018
[  181.844044] RIP: 0010:0x0
[  181.844079] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[  181.844084] RSP: 0018:ffffb593c2b8f7b0 EFLAGS: 00010246
[  181.844093] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
[  181.844099] RDX: ffffb593c2b8f804 RSI: ffffb593c2b8f7e0 RDI: ffff9e3c8e758400
[  181.844105] RBP: ffffb593c2b8f7b8 R08: ffffb593c2b8f9c8 R09: ffffb593c2b8f96c
[  181.844110] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb593c2b8f9c8
[  181.844115] R13: 0000000000000001 R14: ffff9e3c88000000 R15: 0000000000000005
[  181.844121] FS:  00007c6e323bb5c0(0000) GS:ffff9e3f85f80000(0000) knlGS:0000000000000000
[  181.844128] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  181.844134] CR2: ffffffffffffffd6 CR3: 0000000140fbe000 CR4: 00000000003506e0
[  181.844141] Call Trace:
[  181.844146]  <TASK>
[  181.844153]  ? show_regs+0x6d/0x80
[  181.844167]  ? __die+0x24/0x80
[  181.844179]  ? page_fault_oops+0x99/0x1b0
[  181.844192]  ? do_user_addr_fault+0x31d/0x6b0
[  181.844204]  ? exc_page_fault+0x83/0x1b0
[  181.844216]  ? asm_exc_page_fault+0x27/0x30
[  181.844237]  dcn20_get_dcc_compression_cap+0x23/0x30 [amdgpu]
[  181.845115]  amdgpu_dm_plane_validate_dcc.constprop.0+0xe5/0x180 [amdgpu]
[  181.845985]  amdgpu_dm_plane_fill_plane_buffer_attributes+0x300/0x580 [amdgpu]
[  181.846848]  fill_dc_plane_info_and_addr+0x258/0x350 [amdgpu]
[  181.847734]  fill_dc_plane_attributes+0x162/0x350 [amdgpu]
[  181.848748]  dm_update_plane_state.constprop.0+0x4e3/0x6b0 [amdgpu]
[  181.849791]  ? dm_update_plane_state.constprop.0+0x4e3/0x6b0 [amdgpu]
[  181.850840]  amdgpu_dm_atomic_check+0xdfe/0x1760 [amdgpu]

The Linux kernel CVE team has assigned CVE-2024-43899 to this issue.

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

	Fixed in 6.10.5 with commit 974fccd61758
	Fixed in 6.11 with commit ecbf60782662

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-2024-43899
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/display/dc/resource/dcn20/dcn20_resource.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/974fccd61758599a9716c4b909d9226749efe37e
	https://git.kernel.org/stable/c/ecbf60782662f0a388493685b85a645a0ba1613c