From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, andreyknvl@gmail.com,
aryabinin@virtuozzo.com, eberman@codeaurora.org,
elver@google.com, glider@google.com, linux-mm@kvack.org,
mm-commits@vger.kernel.org, torvalds@linux-foundation.org,
vincenzo.frascino@arm.com
Subject: [patch 05/10] kasan: slab: always reset the tag in get_freepointer_safe()
Date: Sat, 22 May 2021 17:41:56 -0700 [thread overview]
Message-ID: <20210523004156.1-UnZ7NxI%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210522174113.47fd4c853c0a1470c57deefa@linux-foundation.org>
From: Alexander Potapenko <glider@google.com>
Subject: kasan: slab: always reset the tag in get_freepointer_safe()
With CONFIG_DEBUG_PAGEALLOC enabled, the kernel should also untag the
object pointer, as done in get_freepointer().
Failing to do so reportedly leads to SLUB freelist corruptions that
manifest as boot-time crashes.
Link: https://lkml.kernel.org/r/20210514072228.534418-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Elliot Berman <eberman@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/slub.c | 1 +
1 file changed, 1 insertion(+)
--- a/mm/slub.c~kasan-slab-always-reset-the-tag-in-get_freepointer_safe
+++ a/mm/slub.c
@@ -301,6 +301,7 @@ static inline void *get_freepointer_safe
if (!debug_pagealloc_enabled_static())
return get_freepointer(s, object);
+ object = kasan_reset_tag(object);
freepointer_addr = (unsigned long)object + s->offset;
copy_from_kernel_nofault(&p, (void **)freepointer_addr, sizeof(p));
return freelist_ptr(s, p, freepointer_addr);
_
next prev parent reply other threads:[~2021-05-23 0:41 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-23 0:41 incoming Andrew Morton
2021-05-23 0:41 ` [patch 01/10] mm/shuffle: fix section mismatch warning Andrew Morton
2021-05-23 0:41 ` [patch 02/10] Revert "mm/gup: check page posion status for coredump." Andrew Morton
2021-05-23 0:41 ` [patch 03/10] ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry Andrew Morton
2021-05-23 0:41 ` [patch 04/10] tools/testing/selftests/exec: fix link error Andrew Morton
2021-05-23 0:41 ` Andrew Morton [this message]
2021-05-23 0:41 ` [patch 06/10] watchdog: reliable handling of timestamps Andrew Morton
2021-05-23 0:42 ` [patch 07/10] linux/bits.h: fix compilation error with GENMASK Andrew Morton
2021-05-23 0:42 ` [patch 08/10] proc: remove Alexey from MAINTAINERS Andrew Morton
2021-05-23 0:42 ` [patch 09/10] lib: kunit: suppress a compilation warning of frame size Andrew Morton
2021-05-23 0:42 ` [patch 10/10] userfaultfd: hugetlbfs: fix new flag usage in error path Andrew Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210523004156.1-UnZ7NxI%akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=andreyknvl@gmail.com \
--cc=aryabinin@virtuozzo.com \
--cc=eberman@codeaurora.org \
--cc=elver@google.com \
--cc=glider@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mm-commits@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=vincenzo.frascino@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.