From patchwork Fri Jun 6 15:03:54 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 356853 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id C5AEC140084; Sat, 7 Jun 2014 01:04:37 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Wsvh4-00064C-Ud; Fri, 06 Jun 2014 15:04:34 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1WsvgS-0005ge-9T for kernel-team@lists.ubuntu.com; Fri, 06 Jun 2014 15:03:56 +0000 Received: from [188.251.61.214] (helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1WsvgR-00060s-WC; Fri, 06 Jun 2014 15:03:56 +0000 From: Luis Henriques To: Heiko Carstens Subject: [3.11.y.z extended stable] Patch "net: filter: s390: fix JIT address randomization" has been added to staging queue Date: Fri, 6 Jun 2014 16:03:54 +0100 Message-Id: <1402067034-11523-1-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 X-Extended-Stable: 3.11 Cc: kernel-team@lists.ubuntu.com, "David S. Miller" , Alexei Starovoitov X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled net: filter: s390: fix JIT address randomization to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 61396813e73095399654fc5aba02bad08ea97ee1 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 14 May 2014 09:48:21 +0200 Subject: net: filter: s390: fix JIT address randomization commit e84d2f8d2ae33c8215429824e1ecf24cbca9645e upstream. This is the s390 variant of Alexei's JIT bug fix. (patch description below stolen from Alexei's patch) bpf_alloc_binary() adds 128 bytes of room to JITed program image and rounds it up to the nearest page size. If image size is close to page size (like 4000), it is rounded to two pages: round_up(4000 + 4 + 128) == 8192 then 'hole' is computed as 8192 - (4000 + 4) = 4188 If prandom_u32() % hole selects a number >= PAGE_SIZE - sizeof(*header) then kernel will crash during bpf_jit_free(): kernel BUG at arch/x86/mm/pageattr.c:887! Call Trace: [] change_page_attr_set_clr+0x135/0x460 [] ? _raw_spin_unlock_irq+0x30/0x50 [] set_memory_rw+0x2f/0x40 [] bpf_jit_free_deferred+0x2d/0x60 [] process_one_work+0x1d8/0x6a0 [] ? process_one_work+0x178/0x6a0 [] worker_thread+0x11c/0x370 since bpf_jit_free() does: unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; struct bpf_binary_header *header = (void *)addr; to compute start address of 'bpf_binary_header' and header->pages will pass junk to: set_memory_rw(addr, header->pages); Fix it by making sure that &header->image[prandom_u32() % hole] and &header are in the same page. Fixes: aa2d2c73c21f2 ("s390/bpf,jit: address randomize and write protect jit code") Reported-by: Alexei Starovoitov Signed-off-by: Heiko Carstens Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- arch/s390/net/bpf_jit_comp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.9.1 diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 8ccd6a669804..63c527eb096f 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -811,7 +811,7 @@ static struct bpf_binary_header *bpf_alloc_binary(unsigned int bpfsize, return NULL; memset(header, 0, sz); header->pages = sz / PAGE_SIZE; - hole = sz - (bpfsize + sizeof(*header)); + hole = min(sz - (bpfsize + sizeof(*header)), PAGE_SIZE - sizeof(*header)); /* Insert random number of illegal instructions before BPF code * and make sure the first instruction starts at an even address. */