[PATCH 0/1] mm: kfence: remove kfence_pool from leak trace

From: yee.lee
Date: Thu Jun 23 2022 - 07:20:09 EST


From: Yee Lee <yee.lee@xxxxxxxxxxxx>

Since the latest patches of kmemleak separated its address management
to two, phys and virt, rb-trees, the kmemleak_free failed to free kfence_pool
in the virt tree. It caused unexpected scan the blocks and triggered
kfence faults.

Reference:
https://lore.kernel.org/linux-mm/20220611035551.1823303-1-patrick.wang.shcn@xxxxxxxxx/

==================================================================
BUG: KFENCE: invalid read in scan_block+0x13c/0x838

Invalid read at 0x000000003dc26873:
scan_block+0x13c/0x838
scan_gray_list+0x1f0/0x478
kmemleak_scan+0x63c/0xd64
kmemleak_write+0x618/0x8cc
full_proxy_write+0x70/0x138
vfs_write+0x108/0x314
ksys_write+0x7c/0x14c
__arm64_sys_write+0x20/0x30
el0_svc_common+0xa8/0x144
do_el0_svc+0x30/0xd4
el0_svc+0x38/0x15c
el0t_64_sync_handler+0x88/0xf8
el0t_64_sync+0x1a0/0x1a4

CPU: 0 PID: 128 Comm: sh Not tainted 5.18.0-mainline-40996-g7d83a175ff4a-dirty #1
Hardware name: linux,dummy-virt (DT)
==================================================================

This patch change to call the memblock alloc with the flag to skip leak tracking.
And the latter kmemleak_free can be removed too.


Yee Lee (1):
mm: kfence: skip kmemleak alloc in kfence_pool

mm/kfence/core.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

--
2.18.0