6.5.5: UBSAN: radeon_atombios.c: index 1 is out of range for type 'UCHAR [1]'

[Justin Piszcz]

Hello,

Kernel: 6.5.5
Arch: x86_64
Distribution: Debian testing

Recently, I enabled UBSAN and noticed the following at boot time with
an older AMD graphics card, is this considered normal when using the
AMD firmware-linux-nonfree package?

[ .. ]
[Sun Oct  1 15:59:04 2023] ACPI: bus type drm_connector registered
[Sun Oct  1 15:59:04 2023] [drm] radeon kernel modesetting enabled.
[Sun Oct  1 15:59:04 2023] [drm] initializing kernel modesetting
(CEDAR 0x1002:0x68E1 0x1787:0x3000 0x00).
[Sun Oct  1 15:59:04 2023] ATOM BIOS: PARK
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: VRAM: 1024M
0x0000000000000000 - 0x000000003FFFFFFF (1024M used)
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: GTT: 1024M
0x0000000040000000 - 0x000000007FFFFFFF
[Sun Oct  1 15:59:04 2023] [drm] Detected VRAM RAM=1024M, BAR=256M
[Sun Oct  1 15:59:04 2023] [drm] RAM width 64bits DDR
[Sun Oct  1 15:59:04 2023] [drm] radeon: 1024M of VRAM memory ready
[Sun Oct  1 15:59:04 2023] [drm] radeon: 1024M of GTT memory ready.
[Sun Oct  1 15:59:04 2023] [drm] Loading CEDAR Microcode
[Sun Oct  1 15:59:04 2023] [drm] Internal thermal controller with fan control
[Sun Oct  1 15:59:04 2023]
================================================================================
[Sun Oct  1 15:59:04 2023] UBSAN: array-index-out-of-bounds in
drivers/gpu/drm/radeon/radeon_atombios.c:2620:43
[Sun Oct  1 15:59:04 2023] index 1 is out of range for type 'UCHAR [1]'
[Sun Oct  1 15:59:04 2023] CPU: 5 PID: 1 Comm: swapper/0 Tainted: G
            T  6.5.5 #13 55df8de52754ef95effc50a55e9206abdea304ac
[Sun Oct  1 15:59:04 2023] Hardware name: Supermicro X9SRL-F/X9SRL-F,
BIOS 3.3 11/13/2018
[Sun Oct  1 15:59:04 2023] Call Trace:
[Sun Oct  1 15:59:04 2023]  <TASK>
[Sun Oct  1 15:59:04 2023]  dump_stack_lvl+0x36/0x50
[Sun Oct  1 15:59:04 2023]  __ubsan_handle_out_of_bounds+0xc7/0x110
[Sun Oct  1 15:59:04 2023]  radeon_atombios_get_power_modes+0x87a/0x8f0
[Sun Oct  1 15:59:04 2023]  radeon_pm_init+0x13a/0x7e0
[Sun Oct  1 15:59:04 2023]  evergreen_init+0x13d/0x3d0
[Sun Oct  1 15:59:04 2023]  radeon_device_init+0x60a/0xbf0
[Sun Oct  1 15:59:04 2023]  radeon_driver_load_kms+0xb1/0x250
[Sun Oct  1 15:59:04 2023]  drm_dev_register+0xfc/0x250
[Sun Oct  1 15:59:04 2023]  radeon_pci_probe+0xd0/0x150
[Sun Oct  1 15:59:04 2023]  pci_device_probe+0x97/0x130
[Sun Oct  1 15:59:04 2023]  really_probe+0xbe/0x2f0
[Sun Oct  1 15:59:04 2023]  ? __pfx___driver_attach+0x10/0x10
[Sun Oct  1 15:59:04 2023]  __driver_probe_device+0x6e/0x120
[Sun Oct  1 15:59:04 2023]  driver_probe_device+0x1a/0x90
[Sun Oct  1 15:59:04 2023]  __driver_attach+0xd4/0x170
[Sun Oct  1 15:59:04 2023]  bus_for_each_dev+0x87/0xe0
[Sun Oct  1 15:59:04 2023]  bus_add_driver+0xf3/0x1f0
[Sun Oct  1 15:59:04 2023]  driver_register+0x58/0x120
[Sun Oct  1 15:59:04 2023]  ? __pfx_radeon_module_init+0x10/0x10
[Sun Oct  1 15:59:04 2023]  do_one_initcall+0x93/0x4a0
[Sun Oct  1 15:59:04 2023]  kernel_init_freeable+0x301/0x580
[Sun Oct  1 15:59:04 2023]  ? __pfx_kernel_init+0x10/0x10
[Sun Oct  1 15:59:04 2023]  kernel_init+0x15/0x1b0
[Sun Oct  1 15:59:04 2023]  ret_from_fork+0x2f/0x50
[Sun Oct  1 15:59:04 2023]  ? __pfx_kernel_init+0x10/0x10
[Sun Oct  1 15:59:04 2023]  ret_from_fork_asm+0x1b/0x30
[Sun Oct  1 15:59:04 2023]  </TASK>
[Sun Oct  1 15:59:04 2023]
================================================================================
[Sun Oct  1 15:59:04 2023] [drm] radeon: dpm initialized
[Sun Oct  1 15:59:04 2023] [drm] GART: num cpu pages 262144, num gpu
pages 262144
[Sun Oct  1 15:59:04 2023] [drm] enabling PCIE gen 2 link speeds,
disable with radeon.pcie_gen2=0
[Sun Oct  1 15:59:04 2023] [drm] PCIE GART of 1024M enabled (table at
0x000000000014C000).
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: WB enabled
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: fence driver on ring 0
use gpu addr 0x0000000040000c00
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: fence driver on ring 3
use gpu addr 0x0000000040000c0c
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: fence driver on ring 5
use gpu addr 0x000000000005c418
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: radeon: MSI limited to 32-bit
[Sun Oct  1 15:59:04 2023] radeon 0000:03:00.0: radeon: using MSI.
[Sun Oct  1 15:59:04 2023] [drm] radeon: irq initialized.

Regards,
Justin