mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-22 03:27:30 -04:00
Code Issues Packages Projects Releases Wiki Activity

kfence: fix KASAN HW tags bypass via runtime sample_interval change

Browse Source 
If a user writes a non-zero value to the sample_interval module parameter
at runtime, the missing KASAN HW tags check in the late init path allows
KFENCE to be enabled alongside KASAN HW tags, bypassing the boot
restriction.

This patch adds the missing check to param_set_sample_interval() to reject
the parameter change if KASAN HW tags are enabled.

Link: https://lore.kernel.org/20260507095237.741017-1-glider@google.com
Fixes: 09833d99db ("mm/kfence: disable KFENCE upon KASAN HW tags enablement")
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Pimyn Girgis <pimyn@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alexander Potapenko
2026-05-07 11:52:37 +02:00
committed by Andrew Morton
parent 83544c68f7
commit e4f5f6f3c1
1 changed files with 5 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
mm/kfence/core.c
View File

@@ -77,6 +77,11 @@ static int param_set_sample_interval(const char *val, const struct kernel_param
WRITE_ONCE(kfence_enabled, false);
}
if (num && kasan_hw_tags_enabled()) {
pr_info("disabled as KASAN HW tags are enabled\n");
return -EINVAL;
}
*((unsigned long *)kp->arg) = num;
if (num && !READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING)