From: Marco Elver <elver@google.com>
To: andrey.konovalov@linux.dev
Cc: Alexander Potapenko <glider@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Andrey Konovalov <andreyknvl@google.com>
Subject: Re: [PATCH] kasan: better invalid/double-free report header
Date: Mon, 12 Sep 2022 19:17:20 +0200 [thread overview]
Message-ID: <CANpmjNMmDyjmYLfqCNdrksbN9BndjerzNTfdKLDQS_7etrNXMA@mail.gmail.com> (raw)
In-Reply-To: <fce40f8dbd160972fe01a1ff39d0c426c310e4b7.1662852281.git.andreyknvl@google.com>
On Sun, 11 Sept 2022 at 01:25, <andrey.konovalov@linux.dev> wrote:
>
> From: Andrey Konovalov <andreyknvl@google.com>
>
> Update the report header for invalid- and double-free bugs to contain
> the address being freed:
>
> BUG: KASAN: invalid-free in kfree+0x280/0x2a8
> Free of addr ffff00000beac001 by task kunit_try_catch/99
It wouldn't hurt showing a full before vs. after report here in the
commit message for ease of reviewing.
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
> ---
> mm/kasan/report.c | 23 ++++++++++++++++-------
> mm/kasan/report_generic.c | 3 ++-
> mm/kasan/report_tags.c | 2 +-
> 3 files changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 39e8e5a80b82..df3602062bfd 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -175,17 +175,14 @@ static void end_report(unsigned long *flags, void *addr)
>
> static void print_error_description(struct kasan_report_info *info)
> {
> - if (info->type == KASAN_REPORT_INVALID_FREE) {
> - pr_err("BUG: KASAN: invalid-free in %pS\n", (void *)info->ip);
> - return;
> - }
> + pr_err("BUG: KASAN: %s in %pS\n", info->bug_type, (void *)info->ip);
>
> - if (info->type == KASAN_REPORT_DOUBLE_FREE) {
> - pr_err("BUG: KASAN: double-free in %pS\n", (void *)info->ip);
> + if (info->type != KASAN_REPORT_ACCESS) {
> + pr_err("Free of addr %px by task %s/%d\n",
> + info->access_addr, current->comm, task_pid_nr(current));
> return;
> }
>
> - pr_err("BUG: KASAN: %s in %pS\n", info->bug_type, (void *)info->ip);
> if (info->access_size)
> pr_err("%s of size %zu at addr %px by task %s/%d\n",
> info->is_write ? "Write" : "Read", info->access_size,
> @@ -420,6 +417,18 @@ static void complete_report_info(struct kasan_report_info *info)
> } else
> info->cache = info->object = NULL;
>
> + switch (info->type) {
> + case KASAN_REPORT_INVALID_FREE:
> + info->bug_type = "invalid-free";
> + break;
> + case KASAN_REPORT_DOUBLE_FREE:
> + info->bug_type = "double-free";
> + break;
> + default:
> + /* bug_type filled in by kasan_complete_mode_report_info. */
> + break;
> + }
> +
> /* Fill in mode-specific report info fields. */
> kasan_complete_mode_report_info(info);
> }
> diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
> index 087c1d8c8145..043c94b04605 100644
> --- a/mm/kasan/report_generic.c
> +++ b/mm/kasan/report_generic.c
> @@ -132,7 +132,8 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
> struct kasan_alloc_meta *alloc_meta;
> struct kasan_free_meta *free_meta;
>
> - info->bug_type = get_bug_type(info);
> + if (!info->bug_type)
> + info->bug_type = get_bug_type(info);
>
> if (!info->cache || !info->object)
> return;
> diff --git a/mm/kasan/report_tags.c b/mm/kasan/report_tags.c
> index d3510424d29b..ecede06ef374 100644
> --- a/mm/kasan/report_tags.c
> +++ b/mm/kasan/report_tags.c
> @@ -37,7 +37,7 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
> bool is_free;
> bool alloc_found = false, free_found = false;
>
> - if (!info->cache || !info->object) {
> + if ((!info->cache || !info->object) && !info->bug_type) {
> info->bug_type = get_common_bug_type(info);
> return;
> }
> --
> 2.25.1
>
prev parent reply other threads:[~2022-09-12 17:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-10 23:25 andrey.konovalov
2022-09-11 11:48 ` Andrey Konovalov
2022-09-12 17:17 ` Marco Elver [this message]
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