From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3AFC73FB84 for ; Mon, 29 Apr 2024 11:23:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714389832; cv=none; b=ink0rmivx4qihwDPoMqIbGaEAXMYTJGMu3Ku6lCYxKw0DbjKYwv63QBXVo6SaCqY39g0uwhlPBBsPQk4e634yFRHj0CNYPy/vc0Ck/HfxyL5YXtjTU4OMJratzzQEMMc2b53K6iDwPU84MjSaiAf5sfnEuhii1djju7xd2MYyCU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714389832; c=relaxed/simple; bh=qtPz4TPPgdJIxdu+3/tWfxUdi5TCFqVXvpT1Mc3GJsY=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=PCu54FRANTrea6wx3FHQYeVBsjLGwonKRnL7I/wNGrV+CmUhh9Fz9OzTDq/SbjJ4JgdKaVLtwPk71ND+Lr/gf86yY63J44FNtxSpqE6+qU2whmB/QK2B3TngSDElsyZ2oVGVB9jeerbFqaRCzDjesWhZ+m8J/ntzr2NPzsJeoHM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NYX2Q93j; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="NYX2Q93j" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79F15C4AF19; Mon, 29 Apr 2024 11:23:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714389831; bh=qtPz4TPPgdJIxdu+3/tWfxUdi5TCFqVXvpT1Mc3GJsY=; h=Subject:To:Cc:From:Date:From; b=NYX2Q93j25ffkidr1lHGs/xDM30hge6fButf2qQSP8qI/ZDX2XWfAsRugpljNoxjX KSE7NBW9+95daXBZNHdkEpzJJUS/SEXzBlkX6mQXH9Yb/GvBMuYuKrRwvzDddk72Qv oJeMqy+dbAkLM+9Ru6iCrtTEDnVk66C6e31MkjGE= Subject: FAILED: patch "[PATCH] mm/hugetlb: fix missing hugetlb_lock for resv uncharge" failed to apply to 6.1-stable tree To: peterx@redhat.com,akpm@linux-foundation.org,almasrymina@google.com,david@redhat.com,stable@vger.kernel.org Cc: From: Date: Mon, 29 Apr 2024 13:23:48 +0200 Message-ID: <2024042948-overstuff-untwist-805f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x b76b46902c2d0395488c8412e1116c2486cdfcb2 # git commit -s git send-email --to '' --in-reply-to '2024042948-overstuff-untwist-805f@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: b76b46902c2d ("mm/hugetlb: fix missing hugetlb_lock for resv uncharge") d4ab0316cc33 ("mm/hugetlb_cgroup: convert hugetlb_cgroup_uncharge_page() to folios") 0356c4b96f68 ("mm/hugetlb: convert free_huge_page to folios") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b76b46902c2d0395488c8412e1116c2486cdfcb2 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Wed, 17 Apr 2024 17:18:35 -0400 Subject: [PATCH] mm/hugetlb: fix missing hugetlb_lock for resv uncharge There is a recent report on UFFDIO_COPY over hugetlb: https://lore.kernel.org/all/000000000000ee06de0616177560@google.com/ 350: lockdep_assert_held(&hugetlb_lock); Should be an issue in hugetlb but triggered in an userfault context, where it goes into the unlikely path where two threads modifying the resv map together. Mike has a fix in that path for resv uncharge but it looks like the locking criteria was overlooked: hugetlb_cgroup_uncharge_folio_rsvd() will update the cgroup pointer, so it requires to be called with the lock held. Link: https://lkml.kernel.org/r/20240417211836.2742593-3-peterx@redhat.com Fixes: 79aa925bf239 ("hugetlb_cgroup: fix reservation accounting") Signed-off-by: Peter Xu Reported-by: syzbot+4b8077a5fccc61c385a1@syzkaller.appspotmail.com Reviewed-by: Mina Almasry Cc: David Hildenbrand Cc: Signed-off-by: Andrew Morton diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 31d00eee028f..53e0ab5c0845 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3268,9 +3268,12 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, rsv_adjust = hugepage_subpool_put_pages(spool, 1); hugetlb_acct_memory(h, -rsv_adjust); - if (deferred_reserve) + if (deferred_reserve) { + spin_lock_irq(&hugetlb_lock); hugetlb_cgroup_uncharge_folio_rsvd(hstate_index(h), pages_per_huge_page(h), folio); + spin_unlock_irq(&hugetlb_lock); + } } if (!memcg_charge_ret)