From: Peter Collingbourne <pcc@google.com>
To: Marco Elver <elver@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Alexander Potapenko <glider@google.com>
Cc: Peter Collingbourne <pcc@google.com>,
Evgenii Stepanov <eugenis@google.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH] kfence: unpoison pool region before use
Date: Fri, 2 Apr 2021 22:13:25 -0700 [thread overview]
Message-ID: <20210403051325.683071-1-pcc@google.com> (raw)
If the memory region allocated by KFENCE had previously been poisoned,
any validity checks done using kasan_byte_accessible() will fail. Fix
it by unpoisoning the memory before using it as the pool region.
Link: https://linux-review.googlesource.com/id/I0af99e9f1c25eaf7e1ec295836b5d148d76940c5
Signed-off-by: Peter Collingbourne <pcc@google.com>
---
mm/kfence/core.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index d53c91f881a4..bb22b0cf77aa 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -633,13 +633,19 @@ static DECLARE_DELAYED_WORK(kfence_timer, toggle_allocation_gate);
void __init kfence_alloc_pool(void)
{
+ void *pool;
+
if (!kfence_sample_interval)
return;
- __kfence_pool = memblock_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
-
- if (!__kfence_pool)
+ pool = memblock_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
+ if (!pool) {
pr_err("failed to allocate pool\n");
+ return;
+ }
+
+ kasan_unpoison_range(pool, KFENCE_POOL_SIZE);
+ __kfence_pool = pool;
}
void __init kfence_init(void)
--
2.31.0.208.g409f899ff0-goog
next reply other threads:[~2021-04-03 5:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-03 5:13 Peter Collingbourne [this message]
2021-04-03 10:03 ` [PATCH] kfence: unpoison pool region before use Marco Elver
2021-04-03 20:40 ` Peter Collingbourne
2021-04-03 22:30 ` Marco Elver
2021-04-03 23:52 ` Andrey Konovalov
2021-04-04 12:09 ` Andrey Konovalov
2021-04-05 19:04 ` Peter Collingbourne
2021-04-03 14:05 ` Andrey Konovalov
2021-04-03 14:45 ` Marco Elver
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