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 0168EC433F5 for ; Tue, 30 Nov 2021 22:09:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344543AbhK3WMC (ORCPT ); Tue, 30 Nov 2021 17:12:02 -0500 Received: from out2.migadu.com ([188.165.223.204]:44263 "EHLO out2.migadu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344585AbhK3WKr (ORCPT ); Tue, 30 Nov 2021 17:10:47 -0500 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=1638310046; 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=AoP2BIKCAOk5uPiTZbwMHsLeQD0XCkLrxAffbVYmGOg=; b=ATD5lSouyvTXgwHP4UiV50lY1OUGrFHOve6euc+dBuVNyPHqzfKsz6Yinvz53OapExb1Gf svoXSOLlANKvOOMbDtVRvj8cNDwu66qgaQ1hDaLx3xL5kvGpBW+3x4gTB63c/KnSFnJuS+ 2oDF8DwiZZL3cRMohQqHvvbXAzBz8GI= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH 22/31] kasan, vmalloc: add vmalloc support to SW_TAGS Date: Tue, 30 Nov 2021 23:07:07 +0100 Message-Id: <0c479434ed079f9e28fe9552adb709645c9d785c.1638308023.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrey Konovalov This patch adds vmalloc tagging support to SW_TAGS KASAN. The changes include: - __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. Signed-off-by: Andrey Konovalov --- include/linux/kasan.h | 17 +++++++++++------ mm/kasan/shadow.c | 6 ++++-- mm/vmalloc.c | 14 ++++++++------ 3 files changed, 23 insertions(+), 14 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index ad4798e77f60..6a2619759e93 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -423,12 +423,14 @@ 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 * __must_check __kasan_unpoison_vmalloc(const void *start, + unsigned long size); +static __always_inline void * __must_check 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); @@ -453,8 +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, bool unique) +{ + 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 fa0c8a750d09..4ca280a96fbc 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 a059b3100c0a..7be18b292679 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2208,7 +2208,7 @@ 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) { @@ -2441,10 +2441,10 @@ 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; } @@ -3752,9 +3752,6 @@ 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 */ @@ -3767,6 +3764,11 @@ 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; -- 2.25.1