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 AE24855E5E; Wed, 21 Feb 2024 13:47:02 +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=1708523222; cv=none; b=fn3YQzHg5Cf2iGG1B0dRsZwIYKsPrNowBYIIHyt4pZU81OYfpeNobYkwHeJdG4gXxcQT6XirQvuzOxOE+RK2QC4RLdnAWl/apZTvGT4KwROb4ZfmOpankWCyB0oD+eE80nNZCNRH6GpAIKFBNnCDT2H8Nlb+dFa3VO1jTWhK8Rc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708523222; c=relaxed/simple; bh=maa3kSqao3fzS4HsaPZsdmTmIuEqBjpk+16VrRT0JXQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YMYDRoft8ILfnQvRZl6f445hts6yTLguEh+dtOXKTG0JePgBE4FMKY67PCKQKEjTV2/ZYHLqdPF4VPGoJH6b4WHt9a9ro0GdcgKwp6Ln50VFB/XBmhsoQWXp/i/xVcUzGTo8Igz3s+hOUUjMQwDFthmL+HQ3rLLaCEx80qbjA38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HXxLfDro; 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="HXxLfDro" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 250DDC433C7; Wed, 21 Feb 2024 13:47:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708523222; bh=maa3kSqao3fzS4HsaPZsdmTmIuEqBjpk+16VrRT0JXQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HXxLfDroNb7NyvVaiPMVPyveN6Q26OEW4m++WotaEKmnPgVP1wBRHw6v0TXeQ03Ja Xmko3wQ+5twLTJsC/zd8I8RVD8iwhVUILPAl0llOJqHcR/7Ek8qMGvRkZNzjWv0Ye5 mb+HzQRKR0hlfNf6TxT2K25nOnKuayd6igIBJoZ0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiangfeng Xiao , Michael Ellerman , Sasha Levin Subject: [PATCH 5.15 371/476] powerpc/kasan: Fix addr error caused by page alignment Date: Wed, 21 Feb 2024 14:07:02 +0100 Message-ID: <20240221130021.749747252@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240221130007.738356493@linuxfoundation.org> References: <20240221130007.738356493@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiangfeng Xiao [ Upstream commit 4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0 ] In kasan_init_region, when k_start is not page aligned, at the begin of for loop, k_cur = k_start & PAGE_MASK is less than k_start, and then `va = block + k_cur - k_start` is less than block, the addr va is invalid, because the memory address space from va to block is not alloced by memblock_alloc, which will not be reserved by memblock_reserve later, it will be used by other places. As a result, memory overwriting occurs. for example: int __init __weak kasan_init_region(void *start, size_t size) { [...] /* if say block(dcd97000) k_start(feef7400) k_end(feeff3fe) */ block = memblock_alloc(k_end - k_start, PAGE_SIZE); [...] for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) { /* at the begin of for loop * block(dcd97000) va(dcd96c00) k_cur(feef7000) k_start(feef7400) * va(dcd96c00) is less than block(dcd97000), va is invalid */ void *va = block + k_cur - k_start; [...] } [...] } Therefore, page alignment is performed on k_start before memblock_alloc() to ensure the validity of the VA address. Fixes: 663c0c9496a6 ("powerpc/kasan: Fix shadow area set up for modules.") Signed-off-by: Jiangfeng Xiao Signed-off-by: Michael Ellerman Link: https://msgid.link/1705974359-43790-1-git-send-email-xiaojiangfeng@huawei.com Signed-off-by: Sasha Levin --- arch/powerpc/mm/kasan/kasan_init_32.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c index f3e4d069e0ba..643fc525897d 100644 --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -64,6 +64,7 @@ int __init __weak kasan_init_region(void *start, size_t size) if (ret) return ret; + k_start = k_start & PAGE_MASK; block = memblock_alloc(k_end - k_start, PAGE_SIZE); if (!block) return -ENOMEM; -- 2.43.0