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 51030C433F5 for ; Tue, 12 Apr 2022 01:09:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243735AbiDLBME (ORCPT ); Mon, 11 Apr 2022 21:12:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348404AbiDLA7V (ORCPT ); Mon, 11 Apr 2022 20:59:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD99D34BAD; Mon, 11 Apr 2022 17:52:36 -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 2F90A6066C; Tue, 12 Apr 2022 00:52:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4E2EC385AC; Tue, 12 Apr 2022 00:52:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649724749; bh=x0vO82PgmsO84hJdKK64ihCc5vTDwaWia8Yej7d8jas=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W6cMSEYfp59/9eP9oQd2YVYrXIguEUx9xXPfA9AFc1OtDQSfE5f2A9ojii0eV7YcE D0518MLj9G8Lfpcb0/fnTEvs0+y/kHLfIQM8pUflfGVsfbbk3dUUBXnIPSnP2h97JM LhNk/khpgTp9JevR3Dci2w73ecAWVcZsWqYUppFIjGnDcS5fICoybNUyyAYKD9Hmqc UZkvqjS9gTAp+OZUJaqUY6/dZcFGgcF2WKrC/yPRKXerhVA8eoV3Nwhvfd0hmXX9e/ NCwjxm2mD4tAT+dTm4Ye88wHja3QTt49FMiHh5+FjwHS/F1J5ogylXhJQxjAanlhBX MgOWwiX2NAPMw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiaoguang Wang , Bodo Stroesser , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 04/11] scsi: target: tcmu: Fix possible page UAF Date: Mon, 11 Apr 2022 20:52:13 -0400 Message-Id: <20220412005222.351554-4-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412005222.351554-1-sashal@kernel.org> References: <20220412005222.351554-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 96601fda47b1..f687481ccfdc 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -1165,6 +1165,7 @@ 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; } @@ -1233,6 +1234,7 @@ static int 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; @@ -1243,7 +1245,6 @@ static int tcmu_vma_fault(struct vm_fault *vmf) return VM_FAULT_NOPAGE; } - get_page(page); vmf->page = page; return 0; } -- 2.35.1