From: Ilya Leoshkevich <iii@linux.ibm.com>
To: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
David Rientjes <rientjes@google.com>,
Heiko Carstens <hca@linux.ibm.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Marco Elver <elver@google.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Pekka Enberg <penberg@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Vasily Gorbik <gor@linux.ibm.com>,
Vlastimil Babka <vbabka@suse.cz>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Hyeonggon Yoo <42.hyeyoo@gmail.com>,
kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-s390@vger.kernel.org,
linux-trace-kernel@vger.kernel.org,
Mark Rutland <mark.rutland@arm.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
Sven Schnelle <svens@linux.ibm.com>
Subject: Re: [PATCH v2 13/33] kmsan: Introduce memset_no_sanitize_memory()
Date: Fri, 08 Dec 2023 15:07:08 +0100 [thread overview]
Message-ID: <69e7bc8e8c8a38c429a793e991e0509cb97a53e1.camel@linux.ibm.com> (raw)
In-Reply-To: <CAG_fn=Vaj3hTRAMxUwofpSMPhFBOizDOWR_An-V9qLNQv-suYw@mail.gmail.com>
On Fri, 2023-12-08 at 14:48 +0100, Alexander Potapenko wrote:
> On Tue, Nov 21, 2023 at 11:06 PM Ilya Leoshkevich <iii@linux.ibm.com>
> wrote:
> >
> > Add a wrapper for memset() that prevents unpoisoning.
>
> We have __memset() already, won't it work for this case?
A problem with __memset() is that, at least for me, it always ends
up being a call. There is a use case where we need to write only 1
byte, so I thought that introducing a call there (when compiling
without KMSAN) would be unacceptable.
> On the other hand, I am not sure you want to preserve the redzone in
> its previous state (unless it's known to be poisoned).
That's exactly the problem with unpoisoning: it removes the distinction
between a new allocation and a UAF.
> You might consider explicitly unpoisoning the redzone instead.
That was my first attempt, but it resulted in test failures due to the
above.
> ...
>
> > +__no_sanitize_memory
> > +static inline void *memset_no_sanitize_memory(void *s, int c,
> > size_t n)
> > +{
> > + return memset(s, c, n);
> > +}
>
> I think depending on the compiler optimizations this might end up
> being a call to normal memset, that would still change the shadow
> bytes.
Interesting, do you have some specific scenario in mind? I vaguely
remember that in the past there were cases when sanitizer annotations
were lost after inlining, but I thought they were sorted out?
And, in any case, if this were to happen, would not it be considered a
compiler bug that needs fixing there, and not in the kernel?
next prev parent reply other threads:[~2023-12-08 14:12 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-21 22:00 [PATCH v2 00/33] kmsan: Enable on s390 Ilya Leoshkevich
2023-11-21 22:00 ` [PATCH v2 01/33] ftrace: Unpoison ftrace_regs in ftrace_ops_list_func() Ilya Leoshkevich
2023-11-22 23:32 ` Steven Rostedt
2023-12-08 14:16 ` Alexander Potapenko
2023-12-08 14:31 ` Steven Rostedt
2023-12-12 2:05 ` Ilya Leoshkevich
2023-11-21 22:00 ` [PATCH v2 02/33] kmsan: Make the tests compatible with kmsan.panic=1 Ilya Leoshkevich
2023-11-21 22:00 ` [PATCH v2 03/33] kmsan: Disable KMSAN when DEFERRED_STRUCT_PAGE_INIT is enabled Ilya Leoshkevich
2023-11-21 22:00 ` [PATCH v2 04/33] kmsan: Increase the maximum store size to 4096 Ilya Leoshkevich
2023-12-08 16:31 ` Alexander Potapenko
2023-11-21 22:00 ` [PATCH v2 05/33] kmsan: Fix is_bad_asm_addr() on arches with overlapping address spaces Ilya Leoshkevich
2023-12-11 9:52 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 06/33] kmsan: Fix kmsan_copy_to_user() " Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 07/33] kmsan: Remove a useless assignment from kmsan_vmap_pages_range_noflush() Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 08/33] kmsan: Remove an x86-specific #include from kmsan.h Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 09/33] kmsan: Introduce kmsan_memmove_metadata() Ilya Leoshkevich
2023-12-08 16:51 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 10/33] kmsan: Expose kmsan_get_metadata() Ilya Leoshkevich
2023-12-11 10:07 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 11/33] kmsan: Export panic_on_kmsan Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 12/33] kmsan: Allow disabling KMSAN checks for the current task Ilya Leoshkevich
2023-12-11 11:50 ` Alexander Potapenko
2023-12-13 15:01 ` Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 13/33] kmsan: Introduce memset_no_sanitize_memory() Ilya Leoshkevich
2023-12-08 13:48 ` Alexander Potapenko
2023-12-08 14:07 ` Ilya Leoshkevich [this message]
2023-12-08 15:25 ` Alexander Potapenko
2023-12-13 1:31 ` Ilya Leoshkevich
2023-12-13 11:32 ` Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 14/33] kmsan: Support SLAB_POISON Ilya Leoshkevich
2023-12-08 13:51 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 15/33] kmsan: Use ALIGN_DOWN() in kmsan_get_metadata() Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 16/33] mm: slub: Let KMSAN access metadata Ilya Leoshkevich
2023-11-30 15:26 ` Vlastimil Babka
2023-11-21 22:01 ` [PATCH v2 17/33] mm: kfence: Disable KMSAN when checking the canary Ilya Leoshkevich
2023-12-08 12:53 ` Alexander Potapenko
2023-12-08 13:55 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 18/33] lib/string: Add KMSAN support to strlcpy() and strlcat() Ilya Leoshkevich
2023-12-08 16:50 ` Alexander Potapenko
2023-12-13 0:53 ` Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 19/33] lib/zlib: Unpoison DFLTCC output buffers Ilya Leoshkevich
2023-12-08 13:32 ` Alexander Potapenko
2023-12-08 14:14 ` Ilya Leoshkevich
2023-12-08 14:25 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 20/33] kmsan: Accept ranges starting with 0 on s390 Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 21/33] s390: Turn off KMSAN for boot, vdso and purgatory Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 22/33] s390: Use a larger stack for KMSAN Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 23/33] s390/boot: Add the KMSAN runtime stub Ilya Leoshkevich
2023-12-08 16:56 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 24/33] s390/checksum: Add a KMSAN check Ilya Leoshkevich
2023-12-08 13:38 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 25/33] s390/cpacf: Unpoison the results of cpacf_trng() Ilya Leoshkevich
2023-12-11 10:36 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 26/33] s390/ftrace: Unpoison ftrace_regs in kprobe_ftrace_handler() Ilya Leoshkevich
2023-12-08 14:18 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 27/33] s390/mm: Define KMSAN metadata for vmalloc and modules Ilya Leoshkevich
2023-12-11 10:13 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 28/33] s390/string: Add KMSAN support Ilya Leoshkevich
2023-12-11 10:49 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 29/33] s390/traps: Unpoison the kernel_stack_overflow()'s pt_regs Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 30/33] s390/uaccess: Add KMSAN support to put_user() and get_user() Ilya Leoshkevich
2023-12-11 10:46 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 31/33] s390/unwind: Disable KMSAN checks Ilya Leoshkevich
2023-11-21 22:01 ` [PATCH v2 32/33] s390: Implement the architecture-specific kmsan functions Ilya Leoshkevich
2023-12-11 10:26 ` Alexander Potapenko
2023-12-11 10:39 ` Ilya Leoshkevich
2023-12-11 10:45 ` Alexander Potapenko
2023-11-21 22:01 ` [PATCH v2 33/33] kmsan: Enable on s390 Ilya Leoshkevich
2023-11-29 9:19 ` Alexander Potapenko
2023-11-29 9:58 ` Ilya Leoshkevich
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