Re: [PATCH] mtd: intel-dg: fix array-index-out-of-bounds in intel_dg_mtd_probe()

[Gustavo A. R. Silva]

On 12/20/25 16:07, Raag Jadav wrote:

On Sat, Dec 20, 2025 at 03:41:49PM +0900, Gustavo A. R. Silva wrote:

Fix the UBSAN: array-index-out-of-bounds issue below by updating
counter nvm->nregions before the first access to flexible-array
member nvm->regions[].

from kernel bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=220823

Dec 15 22:01:52 orpheus kernel: UBSAN: array-index-out-of-bounds in 
/var/tmp/portage/sys-kernel/gentoo-kernel-6.18.1/work/linux-6.18/drivers/mtd/devices/mtd_intel_dg.c:750:15

Notice that this flexible array is annotated with the counted_by()
attribute, hence the counter must always be updated before the
first access to the array.

Already fixed[1], but not sure if it's landed yet.

[1] 
https://lore.kernel.org/linux-mtd/20251111-mtd-nregions-v1-1-61db61e78...@intel.com/

Great! :)

Thanks
-Gustavo