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 40D04C433FE for ; Thu, 6 Oct 2022 15:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231831AbiJFP1Y (ORCPT ); Thu, 6 Oct 2022 11:27:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231596AbiJFP1V (ORCPT ); Thu, 6 Oct 2022 11:27:21 -0400 Received: from mail-m971.mail.163.com (mail-m971.mail.163.com [123.126.97.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B51D6B2751 for ; Thu, 6 Oct 2022 08:27:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=roHdU mVjbO33wXq5iCsNq26tNRZ5hyIMDPxta/AX+nA=; b=cyxZ6EgDhnxBcCJltWBwa 31MXpuUPvtKI1vdbcbiCc2MOIDAnfmHsm5cAdZ1iveN1odDLAiXMqhpzyr9POMdK vdDN8NeJHV4aVzJDWJ6GwO/RwTEOapppsJWfTLQh3UlSBR2wPudtlvjcHyqrMdqH XSDUMEtXeo4B4AnIfZde7o= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by smtp1 (Coremail) with SMTP id GdxpCgBHlYa08z5jwR4jiQ--.19254S2; Thu, 06 Oct 2022 23:26:44 +0800 (CST) From: Zheng Wang To: gregkh@linuxfoundation.org Cc: dimitri.sivanich@hpe.com, arnd@arndb.de, linux-kernel@vger.kernel.org, hackerzheng666@gmail.com, alex000young@gmail.com, security@kernel.org, Zheng Wang Subject: [PATCH v2] misc: sgi-gru: fix use-after-free error in gru_set_context_option, gru_fault and gru_handle_user_call_os Date: Thu, 6 Oct 2022 23:26:43 +0800 Message-Id: <20221006152643.1694235-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: GdxpCgBHlYa08z5jwR4jiQ--.19254S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxGr4xtF4UKw1furyruFWUtwb_yoWruF4Upa 1jg348ArW3XF45urs7ta1kWFW3Ca48JFWUGr9rtwn5ur4FyFs8CryDJas0qr4DurW0qr4a yF45tFnIkan0gaUanT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0ziIPfLUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/1tbiXBSSU1Xl4ZZR4wAAs8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Gts may be freed in gru_check_chiplet_assignment. The caller still use it after that, UAF happens. Fix it by introducing a return value to see if it's in error path or not. Free the gts in caller if gru_check_chiplet_assignment check failed. Fixes: 55484c45dbec ("gru: allow users to specify gru chiplet 2") Reported-by: Zheng Wang Signed-off-by: Zheng Wang --- v2: - commit message changes suggested by Greg v1: https://lore.kernel.org/lkml/CAJedcCzY72jqgF-pCPtx66vXXwdPn-KMagZnqrxcpWw1NxTLaA@mail.gmail.com/ --- drivers/misc/sgi-gru/grufault.c | 15 ++++++++++++--- drivers/misc/sgi-gru/grumain.c | 17 +++++++++++++---- drivers/misc/sgi-gru/grutables.h | 2 +- 3 files changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c index d7ef61e602ed..f1e5b96fef4b 100644 --- a/drivers/misc/sgi-gru/grufault.c +++ b/drivers/misc/sgi-gru/grufault.c @@ -656,7 +656,9 @@ int gru_handle_user_call_os(unsigned long cb) if (ucbnum >= gts->ts_cbr_au_count * GRU_CBR_AU_SIZE) goto exit; - gru_check_context_placement(gts); + ret = gru_check_context_placement(gts); + if (ret) + goto err; /* * CCH may contain stale data if ts_force_cch_reload is set. @@ -677,6 +679,10 @@ int gru_handle_user_call_os(unsigned long cb) exit: gru_unlock_gts(gts); return ret; +err: + gru_unlock_gts(gts); + gru_unload_context(gts, 1); + return -EINVAL; } /* @@ -874,7 +880,7 @@ int gru_set_context_option(unsigned long arg) } else { gts->ts_user_blade_id = req.val1; gts->ts_user_chiplet_id = req.val0; - gru_check_context_placement(gts); + ret = gru_check_context_placement(gts); } break; case sco_gseg_owner: @@ -889,6 +895,9 @@ int gru_set_context_option(unsigned long arg) ret = -EINVAL; } gru_unlock_gts(gts); - + if (ret) { + gru_unload_context(gts, 1); + ret = -EINVAL; + } return ret; } diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c index 9afda47efbf2..79903cf7e706 100644 --- a/drivers/misc/sgi-gru/grumain.c +++ b/drivers/misc/sgi-gru/grumain.c @@ -716,9 +716,10 @@ static int gru_check_chiplet_assignment(struct gru_state *gru, * chiplet. Misassignment can occur if the process migrates to a different * blade or if the user changes the selected blade/chiplet. */ -void gru_check_context_placement(struct gru_thread_state *gts) +int gru_check_context_placement(struct gru_thread_state *gts) { struct gru_state *gru; + int ret = 0; /* * If the current task is the context owner, verify that the @@ -727,14 +728,16 @@ void gru_check_context_placement(struct gru_thread_state *gts) */ gru = gts->ts_gru; if (!gru || gts->ts_tgid_owner != current->tgid) - return; + return ret; if (!gru_check_chiplet_assignment(gru, gts)) { STAT(check_context_unload); - gru_unload_context(gts, 1); + ret = -EINVAL; } else if (gru_retarget_intr(gts)) { STAT(check_context_retarget_intr); } + + return ret; } @@ -919,6 +922,7 @@ vm_fault_t gru_fault(struct vm_fault *vmf) struct gru_thread_state *gts; unsigned long paddr, vaddr; unsigned long expires; + int ret; vaddr = vmf->address; gru_dbg(grudev, "vma %p, vaddr 0x%lx (0x%lx)\n", @@ -934,7 +938,12 @@ vm_fault_t gru_fault(struct vm_fault *vmf) mutex_lock(>s->ts_ctxlock); preempt_disable(); - gru_check_context_placement(gts); + ret = gru_check_context_placement(gts); + if (ret) { + mutex_unlock(>s->ts_ctxlock); + gru_unload_context(gts, 1); + return ret; + } if (!gts->ts_gru) { STAT(load_user_context); diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h index 5efc869fe59a..f4a5a787685f 100644 --- a/drivers/misc/sgi-gru/grutables.h +++ b/drivers/misc/sgi-gru/grutables.h @@ -632,7 +632,7 @@ extern int gru_user_flush_tlb(unsigned long arg); extern int gru_user_unload_context(unsigned long arg); extern int gru_get_exception_detail(unsigned long arg); extern int gru_set_context_option(unsigned long address); -extern void gru_check_context_placement(struct gru_thread_state *gts); +extern int gru_check_context_placement(struct gru_thread_state *gts); extern int gru_cpu_fault_map_id(void); extern struct vm_area_struct *gru_find_vma(unsigned long vaddr); extern void gru_flush_all_tlb(struct gru_state *gru); -- 2.25.1