From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793245049; b=GqT+9trXWmTYEvPfUqmGTTYyI62NzIRnNT6XkGlLQgFORB5tfZR77pFSk1uT8WyvJxTd aLVSfht4MsVhyECChTF43gpYTcSfhFkxFaYaUK/9ZD92obA3MPBc1TfVZEkvquwxnMMkN u+I5lX7NceFW3TyeIoPBRFEPzlUIgkNUsFK1giPfUN6IxaAZywyCT2PpS6uKZLErYgU1w puiRjonjW5Nd5KzFKBANbOu90c/fywLbfXYDlQT3E2V34PIF1mUwLzwjGpZcXI9oaLlJq 1TJR+r8OY+fsCcyVuVejHyMp39G4UrpG7MyDzKxXwAGaYdpscQsDuN0KWGg9XfKEzvg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793245049; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=0TYkcz3oi8Hce4FiXDXGEUsAkrCmcslpFK3fxjBXOUw=; b=ge2VayGYDHFOq5fbP4Oe33OST16zOEe2wvcpfdrDIxSeGZYDw/L2TVsiGusyftvIernj vjoSSybxlG2+4GgLyAQjPnpcFWY1b6DojmskyuXe4FjRXApmn5VhRy0DD44/XJtZtbRSl xFsUb3rNseK6jqzt4H8kgpHwYis2+JjHQSRVBMKsNLhc7z7bETkmGK3QNEWScwi1hlVj0 RKnEUzYfqcueW7Kr8RCPzDywuFdKk8scqUY2NIofJk5BYq6JUNX3/irkKz8+4xD6pgccU hIP3qnsydak5xCkxa0qi1Hyg7+dJANJQPVgdhi8rvUsRWndUp+xmsZ8jQWVgVZPtflA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=EwhdD0ta; arc=none smtp.remote-ip=91.218.175.18 Received: from mta0.migadu.com (out-18.mta0.migadu.com [91.218.175.18]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54F31606A31F for ; Thu, 29 Oct 2026 03:37:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 54F31606A31F Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=EwhdD0ta X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=0TYkcz3oi8Hce4FiXDXGEUsAkrCmcslpFK3fxjBXOUw=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793245046; v=1; x=1793849846; b=EwhdD0taQspvWOf1jRfVxj3kKfbzBcoW1Zh6PIQfZnIs/iXQRocbPuPpJfyNmtIfGQm3KGHU Oh06JsdTIGrNthlWEpv+6QrXR0Zdq/Zd63qqHMkLytRK+ku2AIn63jTXNRRnmPotzFTLiJNDfR3 LZIOVGY4YGYH1FAzvkJnfq8Q= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id b3dc07f6f034e3dc; Thu, 29 Oct 2026 03:37:25 +0000 X-Mizu-Trace-ID: b3dc07f6f034e3dc X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.100.1.1.12\)) Subject: Re: [PATCH 01/15] hugetlbfs: fix integer overflow in fallocate() From: Muchun Song In-Reply-To: <20261028-fixes_hugetlb-v1-1-a0a033db180f@kernel.org> Date: Thu, 29 Oct 2026 11:37:01 +0800 Cc: Oscar Salvador , Naoya Horiguchi , Andrew Morton , Mel Gorman , Andy Whitcroft , Miaohe Lin , Michal Hocko , Rik van Riel , Hugh Dickins , Baolin Wang , Vivek Kasireddy , Dave Airlie , Jason Gunthorpe , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Jonathan Corbet , Shuah Khan , Randy Dunlap , Peter Xu , Breno Leitao , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Gerd Hoffmann , linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, luojiajun , Josef Bacik , stable@kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <497E3E4E-B423-46FA-AB00-5D2ABFB833A0@linux.dev> References: <20261028-fixes_hugetlb-v1-0-a0a033db180f@kernel.org> <20261028-fixes_hugetlb-v1-1-a0a033db180f@kernel.org> To: "David Hildenbrand (Arm)" X-Mailer: Apple Mail (2.3901.100.1.1.12) > On Oct 29, 2026, at 04:13, David Hildenbrand (Arm) = wrote: >=20 > hugetlbfs_fallocate() rounds the range end up by adding hpage_size - 1 > to offset + len. vfs_fallocate()'s existing overflow check only makes > sure that offset + len does not overflow. >=20 > Once we overflow for valid endpoints near LLONG_MAX, we can get a > negative temporary result that is then converted to a very large > huge page index. >=20 > A one-byte allocation ending at LLONG_MAX can therefore consume all > available huge pages. Pages added beyond LLONG_MAX are skipped during > inode eviction, leaking them and triggering the BUG_ON() in = clear_inode(). >=20 > To fix it, calculate the end index in a simpler way that cannot > overflow. This also fixes the signed overflow reported by luojiajun in > 2019. Amazing that you remember something from so long ago! >=20 > Backporting notes: without commit a08c7193e4f18 ("mm/filemap: remove > hugetlb special casing in filemap.c"), remove_inode_hugepages() must > include the final huge page during truncate and eviction. >=20 > Reported-by: luojiajun > Closes: = https://lore.kernel.org/all/1554775226-67213-1-git-send-email-luojiajun3@h= uawei.com/ > Reported-by: Josef Bacik > Fixes: 70c3547e36f5 ("hugetlbfs: add hugetlbfs_fallocate()") > Cc: stable@kernel.org > Signed-off-by: David Hildenbrand (Arm) LGTM. Acked-by: Muchun Song Thanks.