Re: 6.12/BUG: KASAN: slab-use-after-free in m_next at fs/proc/task_mmu.c:187

From: Mikhail Gavrilov
Date: Wed Oct 02 2024 - 16:45:44 EST


On Wed, Oct 2, 2024 at 10:56 PM Lorenzo Stoakes
<lorenzo.stoakes@xxxxxxxxxx> wrote:
> We can reliably repro it with CONFIG_DEBUG_VM_MAPLE_TREE, CONFIG_DEBUG_VM, and
> CONFIG_DEBUG_MAPLE_TREE set, if you set these you should see a report more
> quickly (let us know if you do).

mikhail@primary-ws ~/dmesg> cat .config | grep 'CONFIG_DEBUG_VM_MAPLE_TREE'
# CONFIG_DEBUG_VM_MAPLE_TREE is not set
mikhail@primary-ws ~/dmesg> cat .config | grep 'CONFIG_DEBUG_VM'
CONFIG_DEBUG_VM_IRQSOFF=y
CONFIG_DEBUG_VM=y
# CONFIG_DEBUG_VM_MAPLE_TREE is not set
# CONFIG_DEBUG_VM_RB is not set
CONFIG_DEBUG_VM_PGFLAGS=y
CONFIG_DEBUG_VM_PGTABLE=y
mikhail@primary-ws ~/dmesg> cat .config | grep 'CONFIG_DEBUG_MAPLE_TREE'
# CONFIG_DEBUG_MAPLE_TREE is not set

Fedora's kernel build uses only CONFIG_DEBUG_VM and it's enough for
reproducing this issue.
Anyway I enabled all three options. I'll try to live for a day without
steam launching. In a day I'll write whether it is reproducing without
steam or not.

On Thu, Oct 3, 2024 at 1:32 AM Lorenzo Stoakes
<lorenzo.stoakes@xxxxxxxxxx> wrote:
> Out of curiosity, what GPU are you using? :)

The issue reproduces on all my machines.
One has an AMD Radeon 6900 XT and a second AMD Radeon 7900 XTX.

--
Best Regards,
Mike Gavrilov.