From: Alexander Potapenko <glider@google.com>
To: andrey.konovalov@linux.dev
Cc: Marco Elver <elver@google.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
kasan-dev <kasan-dev@googlegroups.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Andrey Konovalov <andreyknvl@google.com>
Subject: Re: [PATCH mm 06/22] kasan: simplify async check in end_report
Date: Wed, 2 Mar 2022 18:37:34 +0100 [thread overview]
Message-ID: <CAG_fn=UX_hF4RYdCMy-NRC+=KySFLE4wOTiCmzFPBwhieWjz4w@mail.gmail.com> (raw)
In-Reply-To: <1c8ce43f97300300e62c941181afa2eb738965c5.1646237226.git.andreyknvl@google.com>
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On Wed, Mar 2, 2022 at 5:37 PM <andrey.konovalov@linux.dev> wrote:
> From: Andrey Konovalov <andreyknvl@google.com>
>
> Currently, end_report() does not call trace_error_report_end() for bugs
> detected in either async or asymm mode (when kasan_async_fault_possible()
> returns true), as the address of the bad access might be unknown.
>
> However, for asymm mode, the address is known for faults triggered by
> read operations.
>
> Instead of using kasan_async_fault_possible(), simply check that
> the addr is not NULL when calling trace_error_report_end().
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
> mm/kasan/report.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index d60ee8b81e2b..2d892ec050be 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -112,7 +112,7 @@ static void start_report(unsigned long *flags)
>
> static void end_report(unsigned long *flags, unsigned long addr)
> {
> - if (!kasan_async_fault_possible())
> + if (addr)
> trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
>
What happens in the case of a NULL dereference? Don't we want to trigger
the tracepoint as well?
--
Alexander Potapenko
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next prev parent reply other threads:[~2022-03-02 17:38 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-02 16:36 [PATCH mm 00/22] kasan: report clean-ups and improvements andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 01/22] kasan: drop addr check from describe_object_addr andrey.konovalov
2022-03-02 17:27 ` Alexander Potapenko
2022-03-02 16:36 ` [PATCH mm 02/22] kasan: more line breaks in reports andrey.konovalov
2022-03-02 17:28 ` Alexander Potapenko
2022-03-02 16:36 ` [PATCH mm 03/22] kasan: rearrange stack frame info " andrey.konovalov
2022-03-02 17:29 ` Alexander Potapenko
2022-03-02 16:36 ` [PATCH mm 04/22] kasan: improve " andrey.konovalov
2022-03-02 17:31 ` Alexander Potapenko
2022-03-02 16:36 ` [PATCH mm 05/22] kasan: print basic stack frame info for SW_TAGS andrey.konovalov
2022-03-02 17:34 ` Alexander Potapenko
2022-03-08 14:09 ` Andrey Konovalov
2022-03-02 16:36 ` [PATCH mm 06/22] kasan: simplify async check in end_report andrey.konovalov
2022-03-02 17:37 ` Alexander Potapenko [this message]
2022-03-08 14:09 ` Andrey Konovalov
2022-03-02 16:36 ` [PATCH mm 07/22] kasan: simplify kasan_update_kunit_status and call sites andrey.konovalov
2022-03-02 17:46 ` Alexander Potapenko
2022-03-02 16:36 ` [PATCH mm 08/22] kasan: check CONFIG_KASAN_KUNIT_TEST instead of CONFIG_KUNIT andrey.konovalov
2022-03-02 17:57 ` Alexander Potapenko
2022-03-02 16:36 ` [PATCH mm 09/22] kasan: move update_kunit_status to start_report andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 10/22] kasan: move disable_trace_on_warning " andrey.konovalov
2022-03-02 18:00 ` Alexander Potapenko
2022-03-02 16:36 ` [PATCH mm 11/22] kasan: split out print_report from __kasan_report andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 12/22] kasan: simplify kasan_find_first_bad_addr call sites andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 13/22] kasan: restructure kasan_report andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 14/22] kasan: merge __kasan_report into kasan_report andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 15/22] kasan: call print_report from kasan_report_invalid_free andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 16/22] kasan: move and simplify kasan_report_async andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 17/22] kasan: rename kasan_access_info to kasan_report_info andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 18/22] kasan: add comment about UACCESS regions to kasan_report andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 19/22] kasan: respect KASAN_BIT_REPORTED in all reporting routines andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 20/22] kasan: reorder reporting functions andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 21/22] kasan: move and hide kasan_save_enable/restore_multi_shot andrey.konovalov
2022-03-02 16:36 ` [PATCH mm 22/22] kasan: disable LOCKDEP when printing reports andrey.konovalov
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