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 4F478C433EF for ; Fri, 25 Mar 2022 22:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233985AbiCYWo2 (ORCPT ); Fri, 25 Mar 2022 18:44:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233984AbiCYWoH (ORCPT ); Fri, 25 Mar 2022 18:44:07 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6E81209A63 for ; Fri, 25 Mar 2022 15:42:31 -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 sin.source.kernel.org (Postfix) with ESMTPS id 18AF5CE2BA2 for ; Fri, 25 Mar 2022 22:42:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B488C340ED; Fri, 25 Mar 2022 22:42:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648248148; bh=DfkMpvQjo1/Y4wPrwHL6m/QhiLbred/3OVnIiqS9wAg=; h=Date:To:From:Subject:From; b=0EJoGX17pAB/Eu4ULS2ERWYkLcBSYBkP7nEdq+zo+oxu1Z/71rVu8MfQbo+AcQcnu XDt4hVpCWtc8WPOv2ZOYmCG/AEDzWtpIM1cfAxsCBFOhQzhoO6XU+PbnS/b/5s3X7G K4dOZR7hx+gH13T1aPoWXg1hfKbkgKX+mLGS/xkk= Date: Fri, 25 Mar 2022 15:42:27 -0700 To: mm-commits@vger.kernel.org, will@kernel.org, vincenzo.frascino@arm.com, ryabinin.a.a@gmail.com, pcc@google.com, mark.rutland@arm.com, glider@google.com, eugenis@google.com, elver@google.com, dvyukov@google.com, catalin.marinas@arm.com, andreyknvl@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged] kasan-arm64-dont-tag-executable-vmalloc-allocations.patch removed from -mm tree Message-Id: <20220325224228.7B488C340ED@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: kasan, arm64: don't tag executable vmalloc allocations has been removed from the -mm tree. Its filename was kasan-arm64-dont-tag-executable-vmalloc-allocations.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Andrey Konovalov Subject: kasan, arm64: don't tag executable vmalloc allocations Besides asking vmalloc memory to be executable via the prot argument of __vmalloc_node_range() (see the previous patch), the kernel can skip that bit and instead mark memory as executable via set_memory_x(). Once tag-based KASAN modes start tagging vmalloc allocations, executing code from such allocations will lead to the PC register getting a tag, which is not tolerated by the kernel. Generic kernel code typically allocates memory via module_alloc() if it intends to mark memory as executable. (On arm64 module_alloc() uses __vmalloc_node_range() without setting the executable bit). Thus, reset pointer tags of pointers returned from module_alloc(). However, on arm64 there's an exception: the eBPF subsystem. Instead of using module_alloc(), it uses vmalloc() (via bpf_jit_alloc_exec()) to allocate its JIT region. Thus, reset pointer tags of pointers returned from bpf_jit_alloc_exec(). Resetting tags for these pointers results in untagged pointers being passed to set_memory_x(). This causes conflicts in arithmetic checks in change_memory_common(), as vm_struct->addr pointer returned by find_vm_area() is tagged. Reset pointer tag of find_vm_area(addr)->addr in change_memory_common(). Link: https://lkml.kernel.org/r/b7b2595423340cd7d76b770e5d519acf3b72f0ab.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Catalin Marinas Acked-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Mark Rutland Cc: Peter Collingbourne Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arm64/kernel/module.c | 3 ++- arch/arm64/mm/pageattr.c | 2 +- arch/arm64/net/bpf_jit_comp.c | 3 ++- 3 files changed, 5 insertions(+), 3 deletions(-) --- a/arch/arm64/kernel/module.c~kasan-arm64-dont-tag-executable-vmalloc-allocations +++ a/arch/arm64/kernel/module.c @@ -63,7 +63,8 @@ void *module_alloc(unsigned long size) return NULL; } - return p; + /* Memory is intended to be executable, reset the pointer tag. */ + return kasan_reset_tag(p); } enum aarch64_reloc_op { --- a/arch/arm64/mm/pageattr.c~kasan-arm64-dont-tag-executable-vmalloc-allocations +++ a/arch/arm64/mm/pageattr.c @@ -85,7 +85,7 @@ static int change_memory_common(unsigned */ area = find_vm_area((void *)addr); if (!area || - end > (unsigned long)area->addr + area->size || + end > (unsigned long)kasan_reset_tag(area->addr) + area->size || !(area->flags & VM_ALLOC)) return -EINVAL; --- a/arch/arm64/net/bpf_jit_comp.c~kasan-arm64-dont-tag-executable-vmalloc-allocations +++ a/arch/arm64/net/bpf_jit_comp.c @@ -1304,7 +1304,8 @@ u64 bpf_jit_alloc_exec_limit(void) void *bpf_jit_alloc_exec(unsigned long size) { - return vmalloc(size); + /* Memory is intended to be executable, reset the pointer tag. */ + return kasan_reset_tag(vmalloc(size)); } void bpf_jit_free_exec(void *addr) _ Patches currently in -mm which might be from andreyknvl@google.com are stacktrace-add-interface-based-on-shadow-call-stack.patch arm64-scs-save-scs_sp-values-per-cpu-when-switching-stacks.patch arm64-implement-stack_trace_save_shadow.patch kasan-use-stack_trace_save_shadow.patch