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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=KwGf57n+; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 80F09606A326 for ; Fri, 6 Nov 2026 12:41:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=KwGf57n+ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63EBC1F0089F; Fri, 6 Nov 2026 12:41:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793968868; bh=ZMBLae3lRuQDJK5QznjTjPOTuJ0ZooX11mmURXzsTDM=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=KwGf57n+IdbnSA897QNUk9FhDl35OB3Kr0WdR+I9Mzbe3v4qTt3YJfgqGDgLiJMAB r29pxm8iMC+2ftYzjas6w3kIuA2X1WdZpFBl70KY3k70BgHZ13kOef7qLy8hYMydlR +weneF/AeXum482c1y/aCaC6XHpvbVW6w8rvBg7S+nj2m5ll/YDK3JzIuA9TE0/01u GtO3yAGLNy14yqF6Ne1U6ZPS5tJvZKuWF0JOfvRxTyWWq5meJPDEUW5Vq6EUi5TW0I 9+yFtGraxcTbfWi+qnYgORUzIEkhSOCdw7uOUN3fsZ5yEfqmWJnCYyQVXGQLhnz6wu GDBJK7TqukpvQ== Message-ID: <455e9728-33c5-44c0-84ef-d6b764c6d9db@kernel.org> Date: Fri, 6 Nov 2026 13:40:58 +0100 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 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/ksm: avoid unsafe anon rmap dereference in KSM merge To: "Lorenzo Stoakes (ARM)" , Zhao Gongyi Cc: Xu Xin , Chengming Zhou , Andrew Morton , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20261102-ksm-anon-rmap-fix-v1-1-68962acfb59b@kernel.org> <179387163181.11797.15205182972949028650.b4-ty@b4> <75926835-508f-48d3-a5d9-176cea61546d@bytedance.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/6/26 11:06, Lorenzo Stoakes (ARM) wrote: > On Fri, Nov 06, 2026 at 10:43:45AM +0800, Zhao Gongyi wrote: >> I tested Lorenzo's posted patch on Linux 7.3.0-syz-13001714+ >> with CONFIG_KSM=y, CONFIG_KASAN=y and CONFIG_SLUB_RCU_DEBUG=y. >> >> An earlier unpatched run of the fixed-pool KSM/mremap reproducer hit a >> KASAN slab-use-after-free in page_address_in_vma() after about 342 seconds. >> With the patch applied, the workload ran for 12 minutes (1027 KSM full >> scans) without KASAN, BUG or panic. The fork/COW smoke test passed. >> >> ksm_functional_tests reported 8 passes, 1 failure and 1 skip. The >> "ptrace write failed" failure is a known test-environment issue; dmesg >> showed no kernel error. >> >> Tested-by: Zhao Gongyi > > Thanks! Indeed, appreciated! -- Cheers, David