From: Vincenzo Frascino <vincenzo.frascino@arm.com>
To: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Leon Romanovsky <leonro@mellanox.com>,
Andrey Konovalov <andreyknvl@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
Naresh Kamboju <naresh.kamboju@linaro.org>
Subject: [PATCH v3 2/2] kasan: Add explicit preconditions to kasan_report()
Date: Fri, 22 Jan 2021 14:37:48 +0000 [thread overview]
Message-ID: <20210122143748.50089-3-vincenzo.frascino@arm.com> (raw)
In-Reply-To: <20210122143748.50089-1-vincenzo.frascino@arm.com>
With the introduction of KASAN_HW_TAGS, kasan_report() dereferences
the address passed as a parameter.
Add a comment to make sure that the preconditions to the function are
explicitly clarified.
Note: An invalid address (e.g. NULL) passed to the function when,
KASAN_HW_TAGS is enabled, leads to a kernel panic.
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
include/linux/kasan.h | 7 +++++++
mm/kasan/kasan.h | 2 +-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index fe1ae73ff8b5..0aea9e2a2a01 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -333,6 +333,13 @@ static inline void *kasan_reset_tag(const void *addr)
return (void *)arch_kasan_reset_tag(addr);
}
+/**
+ * kasan_report - print a report about a bad memory access detected by KASAN
+ * @addr: address of the bad access
+ * @size: size of the bad access
+ * @is_write: whether the bad access is a write or a read
+ * @ip: instruction pointer for the accessibility check or the bad access itself
+ */
bool kasan_report(unsigned long addr, size_t size,
bool is_write, unsigned long ip);
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index cc4d9e1d49b1..8c706e7652f2 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -209,7 +209,7 @@ bool check_memory_region(unsigned long addr, size_t size, bool write,
static inline bool addr_has_metadata(const void *addr)
{
- return true;
+ return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
}
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
--
2.30.0
next prev parent reply other threads:[~2021-01-22 14:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-22 14:37 [PATCH v3 0/2] kasan: Fix metadata detection for KASAN_HW_TAGS Vincenzo Frascino
2021-01-22 14:37 ` [PATCH v3 1/2] arm64: Improve kernel address detection of __is_lm_address() Vincenzo Frascino
2021-01-22 14:49 ` Catalin Marinas
2021-01-22 14:37 ` Vincenzo Frascino [this message]
2021-01-22 14:46 ` [PATCH v3 2/2] kasan: Add explicit preconditions to kasan_report() Andrey Konovalov
2021-01-22 14:58 ` Vincenzo Frascino
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