kernel UBSAN array-index-out-of-bounds in AMD video card Edit

[Etienne Lorrain]

Ubuntu 24-04 no more start in graphic mode after latest upgrade, only control-alt-f2 to get console.

The driver for Radeon R9 290x/390x generate:
[ 2.812012] UBSAN: array-index-out-of-bounds in /build/linux-yrLejD/linux-6.8.0/drivers/gpu/drm/radeon/radeon_atombios.c:2718:34
[ 2.812454] UBSAN: array-index-out-of-bounds in /build/linux-yrLejD/linux-6.8.0/drivers/gpu/drm/radeon/radeon_atombios.c:2716:55
[ 2.812858] UBSAN: array-index-out-of-bounds in /build/linux-yrLejD/linux-6.8.0/drivers/gpu/drm/radeon/ci_dpm.c:5588:32
[ 2.812860] index 9 is out of range for type 'UCHAR [1]'

[ 3.948792] UBSAN: array-index-out-of-bounds in /build/linux-yrLejD/linux-6.8.0/drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser2.c:680:23
[ 3.948795] index 8 is out of range for type 'atom_gpio_pin_assignment [8]'

[Etienne Lorrain (etienne-lorrain)]

For information, ubuntu-24.04 has updated Linux kernel from 6.5.0-28 to 6.8.0-31

The problem reported is with newer 6.8.0-31, and also failure to reach a working system is only with new kernel.

The previous Linux kernel is still available in the Grub menu, and choosing "6.5.0-28-generic" to boot does bring a working system.

I still get with the older and working kernel:

etienne@etienne-MS-7D77:~$ sudo dmesg | grep -A1 array-
[ 3.078005] UBSAN: array-index-out-of-bounds in /build/linux-hwe-6.5-5nKPnc/linux-hwe-6.5-6.5.0/drivers/gpu/drm/radeon/radeon_atombios.c:2717:34
[ 3.078010] index 18 is out of range for type 'UCHAR [1]'
--
[ 3.078476] UBSAN: array-index-out-of-bounds in /build/linux-hwe-6.5-5nKPnc/linux-hwe-6.5-6.5.0/drivers/gpu/drm/radeon/radeon_atombios.c:2715:55
[ 3.078481] index 1 is out of range for type 'UCHAR [1]'
--
[ 3.078932] UBSAN: array-index-out-of-bounds in /build/linux-hwe-6.5-5nKPnc/linux-hwe-6.5-6.5.0/drivers/gpu/drm/radeon/ci_dpm.c:5588:32
[ 3.078938] index 9 is out of range for type 'UCHAR [1]'
--
[ 4.170748] UBSAN: array-index-out-of-bounds in /build/linux-hwe-6.5-5nKPnc/linux-hwe-6.5-6.5.0/drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser2.c:683:23
[ 4.170803] index 8 is out of range for type 'atom_gpio_pin_assignment [8]'