From patchwork Mon Dec 20 22:01:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12688735 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2CE1C433FE for ; Mon, 20 Dec 2021 22:01:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1D67F6B00AB; Mon, 20 Dec 2021 17:01:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 187E26B00AC; Mon, 20 Dec 2021 17:01:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EF1516B00AE; Mon, 20 Dec 2021 17:01:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0107.hostedemail.com [216.40.44.107]) by kanga.kvack.org (Postfix) with ESMTP id D6C286B00AC for ; Mon, 20 Dec 2021 17:01:26 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 9B28B8A9CB for ; Mon, 20 Dec 2021 22:01:26 +0000 (UTC) X-FDA: 78939544572.07.43D0F5E Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by imf05.hostedemail.com (Postfix) with ESMTP id EDAF9100043 for ; Mon, 20 Dec 2021 22:01:25 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1640037684; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Fqv7h1AsG69rF+aj+JZZwHLPN8HF8k/gQwZkoiZyU8I=; b=nM+WCsrb7UtqE8hBwKzLDTfccSfAZSEKLpCq6kS37wR5jFQ7GPuqtRux7N/X4EqN/zBJEp zTBuWM76mDCHps/xtquu+hkwnvooB8Joythzh0OF4BHU6guJc+2UEFO+vfyUjD2ZF7mrc4 /XEAAYQEiPW4nl58nvwcWp7FQCR5ydY= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Andrew Morton Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, linux-mm@kvack.org, Vincenzo Frascino , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Peter Collingbourne , Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm v4 24/39] kasan, vmalloc: add vmalloc tagging for SW_TAGS Date: Mon, 20 Dec 2021 23:01:03 +0100 Message-Id: <2680386eab3abc80bead51b45fb92fc2dff03a3b.1640036051.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Rspamd-Queue-Id: EDAF9100043 X-Stat-Signature: rwxrm6444dh4bwnjm878o1ezxb335rip Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=nM+WCsrb; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf05.hostedemail.com: domain of andrey.konovalov@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev X-Rspamd-Server: rspam02 X-HE-Tag: 1640037685-310118 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Andrey Konovalov Add vmalloc tagging support to SW_TAGS KASAN. - __kasan_unpoison_vmalloc() now assigns a random pointer tag, poisons the virtual mapping accordingly, and embeds the tag into the returned pointer. - __get_vm_area_node() (used by vmalloc() and vmap()) and pcpu_get_vm_areas() save the tagged pointer into vm_struct->addr (note: not into vmap_area->addr). This requires putting kasan_unpoison_vmalloc() after setup_vmalloc_vm[_locked](); otherwise the latter will overwrite the tagged pointer. The tagged pointer then is naturally propagateed to vmalloc() and vmap(). - vm_map_ram() returns the tagged pointer directly. As a result of this change, vm_struct->addr is now tagged. Enabling KASAN_VMALLOC with SW_TAGS is not yet allowed. Signed-off-by: Andrey Konovalov --- Changes v2->v3: - Drop accidentally added kasan_unpoison_vmalloc() argument for when KASAN is off. - Drop __must_check for kasan_unpoison_vmalloc(), as its result is sometimes intentionally ignored. - Move allowing enabling KASAN_VMALLOC with SW_TAGS into a separate patch. - Update patch description. Changes v1->v2: - Allow enabling KASAN_VMALLOC with SW_TAGS in this patch. --- include/linux/kasan.h | 16 ++++++++++------ mm/kasan/shadow.c | 6 ++++-- mm/vmalloc.c | 14 ++++++++------ 3 files changed, 22 insertions(+), 14 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index da320069e7cf..92c5dfa29a35 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -424,12 +424,13 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end, unsigned long free_region_start, unsigned long free_region_end); -void __kasan_unpoison_vmalloc(const void *start, unsigned long size); -static __always_inline void kasan_unpoison_vmalloc(const void *start, - unsigned long size) +void *__kasan_unpoison_vmalloc(const void *start, unsigned long size); +static __always_inline void *kasan_unpoison_vmalloc(const void *start, + unsigned long size) { if (kasan_enabled()) - __kasan_unpoison_vmalloc(start, size); + return __kasan_unpoison_vmalloc(start, size); + return (void *)start; } void __kasan_poison_vmalloc(const void *start, unsigned long size); @@ -454,8 +455,11 @@ static inline void kasan_release_vmalloc(unsigned long start, unsigned long free_region_start, unsigned long free_region_end) { } -static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size) -{ } +static inline void *kasan_unpoison_vmalloc(const void *start, + unsigned long size) +{ + return (void *)start; +} static inline void kasan_poison_vmalloc(const void *start, unsigned long size) { } diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index 39d0b32ebf70..5a866f6663fc 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -475,12 +475,14 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end, } } -void __kasan_unpoison_vmalloc(const void *start, unsigned long size) +void *__kasan_unpoison_vmalloc(const void *start, unsigned long size) { if (!is_vmalloc_or_module_addr(start)) - return; + return (void *)start; + start = set_tag(start, kasan_random_tag()); kasan_unpoison(start, size, false); + return (void *)start; } /* diff --git a/mm/vmalloc.c b/mm/vmalloc.c index eaacdf3abfa7..c0985f74c0c1 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2209,7 +2209,7 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node) mem = (void *)addr; } - kasan_unpoison_vmalloc(mem, size); + mem = kasan_unpoison_vmalloc(mem, size); if (vmap_pages_range(addr, addr + size, PAGE_KERNEL, pages, PAGE_SHIFT) < 0) { @@ -2442,10 +2442,10 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, return NULL; } - kasan_unpoison_vmalloc((void *)va->va_start, requested_size); - setup_vmalloc_vm(area, va, flags, caller); + area->addr = kasan_unpoison_vmalloc(area->addr, requested_size); + return area; } @@ -3797,9 +3797,6 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, for (area = 0; area < nr_vms; area++) { if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area])) goto err_free_shadow; - - kasan_unpoison_vmalloc((void *)vas[area]->va_start, - sizes[area]); } /* insert all vm's */ @@ -3812,6 +3809,11 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, } spin_unlock(&vmap_area_lock); + /* mark allocated areas as accessible */ + for (area = 0; area < nr_vms; area++) + vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, + vms[area]->size); + kfree(vas); return vms;