From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AEE2C38A02 for ; Mon, 18 Apr 2022 13:12:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242620AbiDRNOR (ORCPT ); Mon, 18 Apr 2022 09:14:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242406AbiDRM7w (ORCPT ); Mon, 18 Apr 2022 08:59:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F2F4255BC; Mon, 18 Apr 2022 05:41:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EF5D8611FE; Mon, 18 Apr 2022 12:41:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F304BC385A7; Mon, 18 Apr 2022 12:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650285669; bh=JL1Fzm5L3B6Voqyw7R6oOuWlRX3RSRLX2xong9QrcAk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=edJ12SJ/DrjfLcCrGI+rLik7S0bDuYCNlts/IM5peAiQJ8tcOhoJzP4uO6CMDAAy1 JGMfdlRr9xTGnJ22Mu/DkRL44B+YxvChIjv/MtNCs1S5ojf+3XcL4Jtf8lLGwQIIcb fO6OFqeIWtiVngd5V8/cTtG6N1bksDYqYGQZ4uyg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bodo Stroesser , Xiaoguang Wang , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 5.10 052/105] scsi: target: tcmu: Fix possible page UAF Date: Mon, 18 Apr 2022 14:12:54 +0200 Message-Id: <20220418121147.961157504@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121145.140991388@linuxfoundation.org> References: <20220418121145.140991388@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiaoguang Wang [ Upstream commit a6968f7a367f128d120447360734344d5a3d5336 ] tcmu_try_get_data_page() looks up pages under cmdr_lock, but it does not take refcount properly and just returns page pointer. When tcmu_try_get_data_page() returns, the returned page may have been freed by tcmu_blocks_release(). We need to get_page() under cmdr_lock to avoid concurrent tcmu_blocks_release(). Link: https://lore.kernel.org/r/20220311132206.24515-1-xiaoguang.wang@linux.alibaba.com Reviewed-by: Bodo Stroesser Signed-off-by: Xiaoguang Wang Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/target_core_user.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index c6950f157b99..c283e45ac300 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -1676,6 +1676,7 @@ static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi) mutex_lock(&udev->cmdr_lock); page = tcmu_get_block_page(udev, dbi); if (likely(page)) { + get_page(page); mutex_unlock(&udev->cmdr_lock); return page; } @@ -1714,6 +1715,7 @@ static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf) /* For the vmalloc()ed cmd area pages */ addr = (void *)(unsigned long)info->mem[mi].addr + offset; page = vmalloc_to_page(addr); + get_page(page); } else { uint32_t dbi; @@ -1724,7 +1726,6 @@ static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf) return VM_FAULT_SIGBUS; } - get_page(page); vmf->page = page; return 0; } -- 2.35.1