From patchwork Thu Aug 23 08:56:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyeongdon Kim X-Patchwork-Id: 10573581 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7D340112E for ; Thu, 23 Aug 2018 08:57:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6B2722BA1D for ; Thu, 23 Aug 2018 08:57:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5F5B32BA25; Thu, 23 Aug 2018 08:57:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id EE1532BA1D for ; Thu, 23 Aug 2018 08:57:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=jDoCegan72p8sciCp8cIzvMHXrSyj+sKnOMI52C/gHo=; b=qN5 kbJMLq6oInV3NHJagB4cNpE3zLZ2Wm3kKjPLPTdDGQu0h05RqwJ5HhN8sEkiYV3bMElcr+xbq+W+Y ng7KwnhNfMfbU1WfpSbRzy8zhgNGggtRT2U1oM/i69xwlDqrEHi4u2CHStcSspSapnWwIWSQEEjrT sHIHOtDd1jWJJVOaaa1lRFJysk54ZduMqACjGrSpdUsaeeHoRvsO+bP9YUmIFAQkOqJbPdtwS3NCC B7aTM1KVvqRlC1Kend8MiwwBSVu3Bhm7BXPZnQpWd1XR/RNOfgPs1WY895aJG2ygmrk+GcIbtRO32 NxpKxBcHmatVD6yttSv4z3/yHFNG6tw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fslQU-0006EW-Cx; Thu, 23 Aug 2018 08:57:10 +0000 Received: from lgeamrelo13.lge.com ([156.147.23.53] helo=lgeamrelo11.lge.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fslQQ-0006D4-TP for linux-arm-kernel@lists.infradead.org; Thu, 23 Aug 2018 08:57:08 +0000 Received: from unknown (HELO lgeamrelo02.lge.com) (156.147.1.126) by 156.147.23.53 with ESMTP; 23 Aug 2018 17:56:51 +0900 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: kyeongdon.kim@lge.com Received: from unknown (HELO localhost.localdomain) (10.168.176.142) by 156.147.1.126 with ESMTP; 23 Aug 2018 17:56:51 +0900 X-Original-SENDERIP: 10.168.176.142 X-Original-MAILFROM: kyeongdon.kim@lge.com From: Kyeongdon Kim To: aryabinin@virtuozzo.com, catalin.marinas@arm.com, will.deacon@arm.com, glider@google.com, dvyukov@google.com Subject: [PATCH v2] arm64: kasan: add interceptors for strcmp/strncmp functions Date: Thu, 23 Aug 2018 17:56:46 +0900 Message-Id: <1535014606-176525-1-git-send-email-kyeongdon.kim@lge.com> X-Mailer: git-send-email 2.6.2 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180823_015707_246925_BB674BD0 X-CRM114-Status: UNSURE ( 6.87 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: robh@kernel.org, Jason@zx2c4.com, ard.biesheuvel@linaro.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, kyeongdon.kim@lge.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch declares strcmp/strncmp as weak symbols. (2 of them are the most used string operations) Original functions declared as weak and strong ones in mm/kasan/kasan.c could replace them. Assembly optimized strcmp/strncmp functions cannot detect KASan bug. But, now we can detect them like the call trace below. ================================================================== BUG: KASAN: use-after-free in platform_match+0x1c/0x5c at addr ffffffc0ad313500 Read of size 1 by task swapper/0/1 CPU: 3 PID: 1 Comm: swapper/0 Tainted: G B 4.9.77+ #1 Hardware name: Generic (DT) based system Call trace: dump_backtrace+0x0/0x2e0 show_stack+0x14/0x1c dump_stack+0x88/0xb0 kasan_object_err+0x24/0x7c kasan_report+0x2f0/0x484 check_memory_region+0x20/0x14c strcmp+0x1c/0x5c platform_match+0x40/0xe4 __driver_attach+0x40/0x130 bus_for_each_dev+0xc4/0xe0 driver_attach+0x30/0x3c bus_add_driver+0x2dc/0x328 driver_register+0x118/0x160 __platform_driver_register+0x7c/0x88 alarmtimer_init+0x154/0x1e4 do_one_initcall+0x184/0x1a4 kernel_init_freeable+0x2ec/0x2f0 kernel_init+0x18/0x10c ret_from_fork+0x10/0x50 In case of xtensa and x86_64 kasan, no need to use this patch now. Signed-off-by: Kyeongdon Kim --- arch/arm64/include/asm/string.h | 5 +++++ arch/arm64/kernel/arm64ksyms.c | 2 ++ arch/arm64/kernel/image.h | 2 ++ arch/arm64/lib/strcmp.S | 3 +++ arch/arm64/lib/strncmp.S | 3 +++ mm/kasan/kasan.c | 23 +++++++++++++++++++++++ 6 files changed, 38 insertions(+) diff --git a/arch/arm64/include/asm/string.h b/arch/arm64/include/asm/string.h index dd95d33..ab60349 100644 --- a/arch/arm64/include/asm/string.h +++ b/arch/arm64/include/asm/string.h @@ -24,9 +24,11 @@ extern char *strchr(const char *, int c); #define __HAVE_ARCH_STRCMP extern int strcmp(const char *, const char *); +extern int __strcmp(const char *, const char *); #define __HAVE_ARCH_STRNCMP extern int strncmp(const char *, const char *, __kernel_size_t); +extern int __strncmp(const char *, const char *, __kernel_size_t); #define __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); @@ -68,6 +70,9 @@ void memcpy_flushcache(void *dst, const void *src, size_t cnt); #define memmove(dst, src, len) __memmove(dst, src, len) #define memset(s, c, n) __memset(s, c, n) +#define strcmp(cs, ct) __strcmp(cs, ct) +#define strncmp(cs, ct, n) __strncmp(cs, ct, n) + #ifndef __NO_FORTIFY #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */ #endif diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c index d894a20..10b1164 100644 --- a/arch/arm64/kernel/arm64ksyms.c +++ b/arch/arm64/kernel/arm64ksyms.c @@ -50,6 +50,8 @@ EXPORT_SYMBOL(strcmp); EXPORT_SYMBOL(strncmp); EXPORT_SYMBOL(strlen); EXPORT_SYMBOL(strnlen); +EXPORT_SYMBOL(__strcmp); +EXPORT_SYMBOL(__strncmp); EXPORT_SYMBOL(memset); EXPORT_SYMBOL(memcpy); EXPORT_SYMBOL(memmove); diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h index a820ed0..5ef7a57 100644 --- a/arch/arm64/kernel/image.h +++ b/arch/arm64/kernel/image.h @@ -110,6 +110,8 @@ __efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area); __efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy); __efistub___memmove = KALLSYMS_HIDE(__pi_memmove); __efistub___memset = KALLSYMS_HIDE(__pi_memset); +__efistub___strcmp = KALLSYMS_HIDE(__pi_strcmp); +__efistub___strncmp = KALLSYMS_HIDE(__pi_strncmp); #endif __efistub__text = KALLSYMS_HIDE(_text); diff --git a/arch/arm64/lib/strcmp.S b/arch/arm64/lib/strcmp.S index 471fe61..0dffef7 100644 --- a/arch/arm64/lib/strcmp.S +++ b/arch/arm64/lib/strcmp.S @@ -60,6 +60,8 @@ tmp3 .req x9 zeroones .req x10 pos .req x11 +.weak strcmp +ENTRY(__strcmp) ENTRY(strcmp) eor tmp1, src1, src2 mov zeroones, #REP8_01 @@ -232,3 +234,4 @@ CPU_BE( orr syndrome, diff, has_nul ) sub result, data1, data2, lsr #56 ret ENDPIPROC(strcmp) +ENDPROC(__strcmp) diff --git a/arch/arm64/lib/strncmp.S b/arch/arm64/lib/strncmp.S index e267044..b2648c7 100644 --- a/arch/arm64/lib/strncmp.S +++ b/arch/arm64/lib/strncmp.S @@ -64,6 +64,8 @@ limit_wd .req x13 mask .req x14 endloop .req x15 +.weak strncmp +ENTRY(__strncmp) ENTRY(strncmp) cbz limit, .Lret0 eor tmp1, src1, src2 @@ -308,3 +310,4 @@ CPU_BE( orr syndrome, diff, has_nul ) mov result, #0 ret ENDPIPROC(strncmp) +ENDPROC(__strncmp) diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index c3bd520..61ad7f1 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -304,6 +304,29 @@ void *memcpy(void *dest, const void *src, size_t len) return __memcpy(dest, src, len); } +#ifdef CONFIG_ARM64 +/* + * Arch arm64 use assembly variant for strcmp/strncmp, + * xtensa use inline asm operations and x86_64 use c one, + * so now this interceptors only for arm64 kasan. + */ +#undef strcmp +int strcmp(const char *cs, const char *ct) +{ + check_memory_region((unsigned long)cs, 1, false, _RET_IP_); + check_memory_region((unsigned long)ct, 1, false, _RET_IP_); + + return __strcmp(cs, ct); +} +#undef strncmp +int strncmp(const char *cs, const char *ct, size_t len) +{ + check_memory_region((unsigned long)cs, len, false, _RET_IP_); + check_memory_region((unsigned long)ct, len, false, _RET_IP_); + + return __strncmp(cs, ct, len); +} +#endif void kasan_alloc_pages(struct page *page, unsigned int order) {