From patchwork Fri Feb 26 01:20:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12105489 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64E6EC433E0 for ; Fri, 26 Feb 2021 01:20:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E650C64EE4 for ; Fri, 26 Feb 2021 01:20:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E650C64EE4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 77FF16B00C2; Thu, 25 Feb 2021 20:20:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 72DD26B00C3; Thu, 25 Feb 2021 20:20:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 61BF06B00C4; Thu, 25 Feb 2021 20:20:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0248.hostedemail.com [216.40.44.248]) by kanga.kvack.org (Postfix) with ESMTP id 49BD96B00C2 for ; Thu, 25 Feb 2021 20:20:14 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 1DC64C5D5 for ; Fri, 26 Feb 2021 01:20:14 +0000 (UTC) X-FDA: 77858663148.25.D3C98CD Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf27.hostedemail.com (Postfix) with ESMTP id A502A80192D5 for ; Fri, 26 Feb 2021 01:20:06 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id DA83364F26; Fri, 26 Feb 2021 01:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614302412; bh=wce53Xwwu9lKx3GmC4ec2EKIUUqHbhyBfKHLHqVMRbA=; h=Date:From:To:Subject:In-Reply-To:From; b=bWED7WbFR9P83v/ZjKKHDjlFrzaMYti4mj4n+w78IS/6cVme7j+BnTLjUiLzzvKot 4PQZDIomXBKBGdiVWLzIygbb9c8ctgXdl/5lNwGSerTKcGY2gE6E94BXdBtcjDcwmO QAFTy2dsGmiHGcFHJRu2WYF1HmV9KcXBSAFBgtzc= Date: Thu, 25 Feb 2021 17:20:11 -0800 From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@google.com, aryabinin@virtuozzo.com, Branislav.Rankov@arm.com, catalin.marinas@arm.com, dvyukov@google.com, elver@google.com, eugenis@google.com, glider@google.com, kevin.brodsky@arm.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, pcc@google.com, torvalds@linux-foundation.org, vincenzo.frascino@arm.com, will.deacon@arm.com Subject: [patch 074/118] kasan: unify large kfree checks Message-ID: <20210226012011.dU6In8D5z%akpm@linux-foundation.org> In-Reply-To: <20210225171452.713967e96554bb6a53e44a19@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: A502A80192D5 X-Stat-Signature: ipgz8bkg761z3weinwb9bwzkpgh588yh Received-SPF: none (linux-foundation.org>: No applicable sender policy available) receiver=imf27; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614302406-842194 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 Subject: kasan: unify large kfree checks Unify checks in kasan_kfree_large() and in kasan_slab_free_mempool() for large allocations as it's done for small kfree() allocations. With this change, kasan_slab_free_mempool() starts checking that the first byte of the memory that's being freed is accessible. Link: https://lkml.kernel.org/r/14ffc4cd867e0b1ed58f7527e3b748a1b4ad08aa.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Peter Collingbourne Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton --- include/linux/kasan.h | 16 ++++++++-------- mm/kasan/common.c | 36 ++++++++++++++++++++++++++---------- 2 files changed, 34 insertions(+), 18 deletions(-) --- a/include/linux/kasan.h~kasan-unify-large-kfree-checks +++ a/include/linux/kasan.h @@ -200,6 +200,13 @@ static __always_inline bool kasan_slab_f return false; } +void __kasan_kfree_large(void *ptr, unsigned long ip); +static __always_inline void kasan_kfree_large(void *ptr) +{ + if (kasan_enabled()) + __kasan_kfree_large(ptr, _RET_IP_); +} + void __kasan_slab_free_mempool(void *ptr, unsigned long ip); static __always_inline void kasan_slab_free_mempool(void *ptr) { @@ -247,13 +254,6 @@ static __always_inline void * __must_che return (void *)object; } -void __kasan_kfree_large(void *ptr, unsigned long ip); -static __always_inline void kasan_kfree_large(void *ptr) -{ - if (kasan_enabled()) - __kasan_kfree_large(ptr, _RET_IP_); -} - /* * Unlike kasan_check_read/write(), kasan_check_byte() is performed even for * the hardware tag-based mode that doesn't rely on compiler instrumentation. @@ -302,6 +302,7 @@ static inline bool kasan_slab_free(struc { return false; } +static inline void kasan_kfree_large(void *ptr) {} static inline void kasan_slab_free_mempool(void *ptr) {} static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object, gfp_t flags) @@ -322,7 +323,6 @@ static inline void *kasan_krealloc(const { return (void *)object; } -static inline void kasan_kfree_large(void *ptr) {} static inline bool kasan_check_byte(const void *address) { return true; --- a/mm/kasan/common.c~kasan-unify-large-kfree-checks +++ a/mm/kasan/common.c @@ -364,6 +364,31 @@ bool __kasan_slab_free(struct kmem_cache return ____kasan_slab_free(cache, object, ip, true); } +static bool ____kasan_kfree_large(void *ptr, unsigned long ip) +{ + if (ptr != page_address(virt_to_head_page(ptr))) { + kasan_report_invalid_free(ptr, ip); + return true; + } + + if (!kasan_byte_accessible(ptr)) { + kasan_report_invalid_free(ptr, ip); + return true; + } + + /* + * The object will be poisoned by kasan_free_pages() or + * kasan_slab_free_mempool(). + */ + + return false; +} + +void __kasan_kfree_large(void *ptr, unsigned long ip) +{ + ____kasan_kfree_large(ptr, ip); +} + void __kasan_slab_free_mempool(void *ptr, unsigned long ip) { struct page *page; @@ -377,10 +402,8 @@ void __kasan_slab_free_mempool(void *ptr * KMALLOC_MAX_SIZE, and kmalloc falls back onto page_alloc. */ if (unlikely(!PageSlab(page))) { - if (ptr != page_address(page)) { - kasan_report_invalid_free(ptr, ip); + if (____kasan_kfree_large(ptr, ip)) return; - } kasan_poison(ptr, page_size(page), KASAN_FREE_PAGE); } else { ____kasan_slab_free(page->slab_cache, ptr, ip, false); @@ -539,13 +562,6 @@ void * __must_check __kasan_krealloc(con return ____kasan_kmalloc(page->slab_cache, object, size, flags); } -void __kasan_kfree_large(void *ptr, unsigned long ip) -{ - if (ptr != page_address(virt_to_head_page(ptr))) - kasan_report_invalid_free(ptr, ip); - /* The object will be poisoned by kasan_free_pages(). */ -} - bool __kasan_check_byte(const void *address, unsigned long ip) { if (!kasan_byte_accessible(address)) {