Re: [PATCH] fork: reset pointer tag of vmapped thread stack before vfree

From: sparkhuang

Date: Fri Aug 07 2026 - 06:43:36 EST


On 2026-08-07 9:27 UTC, David wrote:
> Were you able to reproduce this more than once?

Still trying to reproduce it. So far it has only occurred this once.

> Does this relate to CONFIG_KASAN_STACK?

I'm not entirely sure if it's related.
The configs relevant to this path are:
CONFIG_KASAN_SHADOW_OFFSET=0xefffffc000000000
CONFIG_HAVE_ARCH_KASAN=y
CONFIG_HAVE_ARCH_KASAN_SW_TAGS=y
CONFIG_HAVE_ARCH_KASAN_HW_TAGS=y
CONFIG_HAVE_ARCH_KASAN_VMALLOC=y
CONFIG_CC_HAS_KASAN_GENERIC=y
CONFIG_CC_HAS_KASAN_SW_TAGS=y
CONFIG_KASAN=y
CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX=y
# CONFIG_KASAN_GENERIC is not set
CONFIG_KASAN_SW_TAGS=y
# CONFIG_KASAN_HW_TAGS is not set
CONFIG_KASAN_OUTLINE=y
# CONFIG_KASAN_INLINE is not set
CONFIG_KASAN_STACK=y
CONFIG_KASAN_VMALLOC=y
# CONFIG_KASAN_KUNIT_TEST is not set
# CONFIG_KASAN_EXTRA_INFO is not set

> Can you share the kernel config?

I'll send it to you separately later.

Thanks,
Shaobo