From patchwork Sun Jun 12 21:32:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12878849 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 A3E31CCA480 for ; Sun, 12 Jun 2022 21:32:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236375AbiFLVcs (ORCPT ); Sun, 12 Jun 2022 17:32:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236111AbiFLVco (ORCPT ); Sun, 12 Jun 2022 17:32:44 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 751A3116E; Sun, 12 Jun 2022 14:32:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=tvuIUvh4KMt/W3Ck0YL8jqhN/KST+B/kPdeyBtOnYMI=; b=jOcEWP6MokPpHUTnlAkh/E65mL 4W8V4vdlxVz2zQtkO9qZYuNZFn6zxe5LZMB+22Jesq35WG5x3Nw2E3mICgwIDFOWEmlaEzeLzTZif F1GoRcMUDGfoYNRj1nVAjB22aXZ/MwOO1EqMsv4gwAqSiELfP/UKhYIiEePON6kF+HKG7nHdQzv2v lQDev+2c7TK3GFkWkjZwQ1dgj9RG1XcUcrKpO8SY1zyRMfgip7xKLuuYv2IEupKC4R2Dp5F8os/YI opoHyaafYUTwT8RK0IuVDaP//qQIWKe5VGQMnGY6LVMulBYnbpkT5IkqyQj0zN0ywgWy3VDWwcTGT 66BdCNUQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1o0VC9-00GHpw-CG; Sun, 12 Jun 2022 21:32:29 +0000 From: "Matthew Wilcox (Oracle)" To: Kees Cook Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, Uladzislau Rezki , Zorro Lang , linux-xfs@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH 1/3] usercopy: Handle vm_map_ram() areas Date: Sun, 12 Jun 2022 22:32:25 +0100 Message-Id: <20220612213227.3881769-2-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220612213227.3881769-1-willy@infradead.org> References: <20220612213227.3881769-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org vmalloc does not allocate a vm_struct for vm_map_ram() areas. That causes us to deny usercopies from those areas. This affects XFS which uses vm_map_ram() for its directories. Fix this by calling find_vmap_area() instead of find_vm_area(). Fixes: 0aef499f3172 ("mm/usercopy: Detect vmalloc overruns") Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/vmalloc.h | 1 + mm/usercopy.c | 8 +++++--- mm/vmalloc.c | 2 +- 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index b159c2789961..096d48aa3437 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -215,6 +215,7 @@ extern struct vm_struct *__get_vm_area_caller(unsigned long size, void free_vm_area(struct vm_struct *area); extern struct vm_struct *remove_vm_area(const void *addr); extern struct vm_struct *find_vm_area(const void *addr); +struct vmap_area *find_vmap_area(unsigned long addr); static inline bool is_vm_area_hugepages(const void *addr) { diff --git a/mm/usercopy.c b/mm/usercopy.c index baeacc735b83..fdd1bed3b90a 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -173,7 +173,7 @@ static inline void check_heap_object(const void *ptr, unsigned long n, } if (is_vmalloc_addr(ptr)) { - struct vm_struct *area = find_vm_area(ptr); + struct vmap_area *area = find_vmap_area((unsigned long)ptr); unsigned long offset; if (!area) { @@ -181,8 +181,10 @@ static inline void check_heap_object(const void *ptr, unsigned long n, return; } - offset = ptr - area->addr; - if (offset + n > get_vm_area_size(area)) + /* XXX: We should also abort for free vmap_areas */ + + offset = (unsigned long)ptr - area->va_start; + if ((unsigned long)ptr + n > area->va_end) usercopy_abort("vmalloc", NULL, to_user, offset, n); return; } diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 07db42455dd4..effd1ff6a4b4 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1798,7 +1798,7 @@ static void free_unmap_vmap_area(struct vmap_area *va) free_vmap_area_noflush(va); } -static struct vmap_area *find_vmap_area(unsigned long addr) +struct vmap_area *find_vmap_area(unsigned long addr) { struct vmap_area *va; From patchwork Sun Jun 12 21:32:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12878846 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 6F4CCCCA47F for ; Sun, 12 Jun 2022 21:32:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230500AbiFLVcp (ORCPT ); Sun, 12 Jun 2022 17:32:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236298AbiFLVcn (ORCPT ); Sun, 12 Jun 2022 17:32:43 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 467EF9FDF; Sun, 12 Jun 2022 14:32:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=KF4owYCbPISYV5a61DiGRvGs/L1LMsz9ReyZ7eXT5t8=; b=geEs3gAVKXk3eNcQdArpYi2DVd f/MN4q94FG7FHdgrWVmDI4vEtNGBpS1vD/DP2rHs7ji3PrgfGGHOWvn8A3AAmpRzatm8leS4fNMaR Fs6S3luOZoQnLu1wdgThCd5i4g41xF0vblXF68HK3PGR3NF5mHXwdGlK8f7j8EYhpBEMYEy9oRHEH qlEW7b8tnYQ0rBpT67IXfWPu99LTz+lOBZmsIyf5LrvwXzKFSHCbS4hUlucLJWK2Wrj8/2TQSpg3W i9qz6yiljtaOFgTf83pXjguAzUIl6miPCNqPkGAOUJitBDthtLjXjcCzOkxJg685Cs7EdPJSyQkRX IVlGdg9w==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1o0VC9-00GHpy-EN; Sun, 12 Jun 2022 21:32:29 +0000 From: "Matthew Wilcox (Oracle)" To: Kees Cook Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, Uladzislau Rezki , Zorro Lang , linux-xfs@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH 2/3] usercopy: Cast pointer to an integer once Date: Sun, 12 Jun 2022 22:32:26 +0100 Message-Id: <20220612213227.3881769-3-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220612213227.3881769-1-willy@infradead.org> References: <20220612213227.3881769-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Get rid of a lot of annoying casts by setting 'addr' once at the top of the function. Signed-off-by: Matthew Wilcox (Oracle) --- mm/usercopy.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/usercopy.c b/mm/usercopy.c index fdd1bed3b90a..31deee7dd2f5 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -161,19 +161,20 @@ static inline void check_bogus_address(const unsigned long ptr, unsigned long n, static inline void check_heap_object(const void *ptr, unsigned long n, bool to_user) { + uintptr_t addr = (uintptr_t)ptr; struct folio *folio; if (is_kmap_addr(ptr)) { - unsigned long page_end = (unsigned long)ptr | (PAGE_SIZE - 1); + unsigned long page_end = addr | (PAGE_SIZE - 1); - if ((unsigned long)ptr + n - 1 > page_end) + if (addr + n - 1 > page_end) usercopy_abort("kmap", NULL, to_user, offset_in_page(ptr), n); return; } if (is_vmalloc_addr(ptr)) { - struct vmap_area *area = find_vmap_area((unsigned long)ptr); + struct vmap_area *area = find_vmap_area(addr); unsigned long offset; if (!area) { @@ -183,8 +184,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n, /* XXX: We should also abort for free vmap_areas */ - offset = (unsigned long)ptr - area->va_start; - if ((unsigned long)ptr + n > area->va_end) + offset = addr - area->va_start; + if (addr + n > area->va_end) usercopy_abort("vmalloc", NULL, to_user, offset, n); return; } From patchwork Sun Jun 12 21:32:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12878847 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 C5F91CCA473 for ; Sun, 12 Jun 2022 21:32:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236182AbiFLVcp (ORCPT ); Sun, 12 Jun 2022 17:32:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235950AbiFLVcn (ORCPT ); Sun, 12 Jun 2022 17:32:43 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4692D9FE8; Sun, 12 Jun 2022 14:32:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=HTrppkgyoE0jfkD/I3hwHGO9wel7JMRK5JWmxra0aTw=; b=SEdm11PHMGs3xIT5eFgs1AaLQw wBdGhsxowR+3VG3Z0qlqYVd4ShqfwhcvCeXebJDQgFdY21nGO8jGU1DiQ9AnXML62aXC9T9iJ+xqE ZaQFMUEEbXRdl1IMHc60ASgvvamq7MuPHSP1mYdaxzNfDsL6pe3370ki95kajTAbs4E9G8M7XpSva qayDemMjdO4a79683xTqgJLYpn/2Q+rd2YonUuDU7DgtZ7ppIissSTdoJs4IUW+zX/+2vkE+ezHUC tJjdE39HiA2gssJMq9StqsbNVvNpaQY/pdSNrHJbus6q0krzIq7U/nYgXzmP4Q3fh+G+ICbIlUBSl lFYersDQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1o0VC9-00GHq0-GJ; Sun, 12 Jun 2022 21:32:29 +0000 From: "Matthew Wilcox (Oracle)" To: Kees Cook Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, Uladzislau Rezki , Zorro Lang , linux-xfs@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH 3/3] usercopy: Make usercopy resilient against ridiculously large copies Date: Sun, 12 Jun 2022 22:32:27 +0100 Message-Id: <20220612213227.3881769-4-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220612213227.3881769-1-willy@infradead.org> References: <20220612213227.3881769-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org If 'n' is so large that it's negative, we might wrap around and mistakenly think that the copy is OK when it's not. Such a copy would probably crash, but just doing the arithmetic in a more simple way lets us detect and refuse this case. Signed-off-by: Matthew Wilcox (Oracle) --- mm/usercopy.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/mm/usercopy.c b/mm/usercopy.c index 31deee7dd2f5..ff16083cf1c8 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -162,20 +162,18 @@ static inline void check_heap_object(const void *ptr, unsigned long n, bool to_user) { uintptr_t addr = (uintptr_t)ptr; + unsigned long offset; struct folio *folio; if (is_kmap_addr(ptr)) { - unsigned long page_end = addr | (PAGE_SIZE - 1); - - if (addr + n - 1 > page_end) - usercopy_abort("kmap", NULL, to_user, - offset_in_page(ptr), n); + offset = offset_in_page(ptr); + if (n > PAGE_SIZE - offset) + usercopy_abort("kmap", NULL, to_user, offset, n); return; } if (is_vmalloc_addr(ptr)) { struct vmap_area *area = find_vmap_area(addr); - unsigned long offset; if (!area) { usercopy_abort("vmalloc", "no area", to_user, 0, n); @@ -184,9 +182,10 @@ static inline void check_heap_object(const void *ptr, unsigned long n, /* XXX: We should also abort for free vmap_areas */ - offset = addr - area->va_start; - if (addr + n > area->va_end) + if (n > area->va_end - addr) { + offset = addr - area->va_start; usercopy_abort("vmalloc", NULL, to_user, offset, n); + } return; } @@ -199,8 +198,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n, /* Check slab allocator for flags and size. */ __check_heap_object(ptr, n, folio_slab(folio), to_user); } else if (folio_test_large(folio)) { - unsigned long offset = ptr - folio_address(folio); - if (offset + n > folio_size(folio)) + offset = ptr - folio_address(folio); + if (n > folio_size(folio) - offset) usercopy_abort("page alloc", NULL, to_user, offset, n); } }