From: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
To: Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Borislav Petkov <bp@alien8.de>,
x86@kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>,
Mike Rapoport <rppt@kernel.org>, Lorenzo Stoakes <ljs@kernel.org>,
Toshi Kani <toshi.kani@hpe.com>,
linux-mm@kvack.org, regressions@lists.linux.dev,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/mm: avoid a reclaiming allocation in pud_free_pmd_page()
Date: Wed, 23 Sep 2026 21:33:15 +0500 [thread overview]
Message-ID: <20260923163315.275046-1-mikhail.v.gavrilov@gmail.com> (raw)
In-Reply-To: <20260916062222.27347-1-mikhail.v.gavrilov@gmail.com>
Hi,
The lock cycle this patch breaks has meanwhile reached released stable
kernels: d5d8b8662e6e ("x86/mm/pat: Acquire init_mm read lock on
attribute changes to avoid UAF") went out in 7.2.7 and 6.18.53 on
Sep 21. Both trees already carry 26444eb71465 ("mm/vmalloc: acquire
init_mm lock on huge vmap to avoid ptdump UAF"), and pud_free_pmd_page()
there still allocates with GFP_KERNEL under the init_mm lock, so the
cycle quoted in the patch exists there too, not only in 7.3-rc.
The patch still applies cleanly to current mainline and next-20260922,
and the reproducer below the scissors of the original mail works
unchanged.
Dave, could this go in through x86/urgent for 7.3? Lorenzo, since the
rule it applies comes from your series, a review from you would help.
If either of you would rather fix it differently, I am happy to respin.
--
Thanks,
Mikhail
next prev parent reply other threads:[~2026-09-23 16:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-16 6:22 [PATCH] x86/mm: avoid a reclaiming allocation in pud_free_pmd_page() Mikhail Gavrilov
2026-09-23 16:33 ` Mikhail Gavrilov [this message]
2026-09-23 18:38 ` Pedro Falcato
2026-09-23 22:26 ` Mikhail Gavrilov
2026-09-23 22:53 ` Dave Hansen
2026-09-23 23:03 ` Mikhail Gavrilov
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=20260923163315.275046-1-mikhail.v.gavrilov@gmail.com \
--to=mikhail.v.gavrilov@gmail.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ljs@kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=regressions@lists.linux.dev \
--cc=rppt@kernel.org \
--cc=tglx@kernel.org \
--cc=toshi.kani@hpe.com \
--cc=x86@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox