From patchwork Fri Jan 20 07:03:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 13109282 X-Patchwork-Delegate: bpf@iogearbox.net 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 3B7B1C05027 for ; Fri, 20 Jan 2023 07:04:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229573AbjATHEl (ORCPT ); Fri, 20 Jan 2023 02:04:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229814AbjATHEk (ORCPT ); Fri, 20 Jan 2023 02:04:40 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 880ED241D9 for ; Thu, 19 Jan 2023 23:04:39 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id dw9so4738980pjb.5 for ; Thu, 19 Jan 2023 23:04:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=yqzLD9MYr6KiuRpe9sBVIUYjbcoAjTXay8FSvvNcEzA=; b=gt/CfO6t5JjH8WUQDRYfLn1I7TT39faaIUUenEuJQNmjG9BL2PWBE0H9aNMCF0Gm5I nAmR35nyDyGMxjkFyFFxq+bL9sR/voBSe3TrKq4BMgpVVBMNmXe+f8V12oKfGSSoI06i GwoQWJ796thu/yrFNPdLLrudYybSuTX2H/dy6D4eL9fdHxCmkWHVFuE/n63iMzka/Pfb MbbPJS1fhuxVWD64Hk2xYQAJsTaKlSjxLneOsP0RjEJLb1zKlrmBq94RlQasRgkkMhg5 TQC+WFJgDJp0m6/TS7LwEFGA49MahNTdu3U5K4GOmlZBRAuYmu/2kzwF6zAPMOuk9bEm nnUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=yqzLD9MYr6KiuRpe9sBVIUYjbcoAjTXay8FSvvNcEzA=; b=JD6zEAaVGCl/+nSjh+GBSkipaN5kS97zLAz8toaH6nsUO0r/OIVznda3SlZ74GbREe 8y5D/MhgKHFaoJdGttSz/Ee4IiaiMHCX2R7JL4agUCZgUEVbW8X9cDG43UoWoXeut2dK 4YoeRQNx7TV7WDSl/4KalfTBByPQAbYfsOTtIG2eMQVXpnanS3ECbJ9BJw9hcT7iZPRP bMuXfBftnS6vR+r27vnNPMOyBm/gf0QeyR3Jbn/VOr/tGtSFY1oU/jYRysXRQryoZq4N PaEc2Aej1nIqryTKXE+6ibwAAHyh0EF+QefXhK2ztsSL/hUvtgkW9NqQbo6VnfBDCCtz xvfw== X-Gm-Message-State: AFqh2kovXz9UaTLy6oIPpn8VkQKLPvUxlBo8w6muPsjdf72nEx7h8xq0 0GdgOGAwv+IDCM4eWR9GuvuSfTQl6qE= X-Google-Smtp-Source: AMrXdXsLyhjnJh+jqTfhEbfWRM9YZ5TDPsHh8jRgF7xPHpBWUUBVpZPj3HbIq4l4vRXenOq879I7gw== X-Received: by 2002:a17:90a:4964:b0:223:a079:7354 with SMTP id c91-20020a17090a496400b00223a0797354mr14508867pjh.15.1674198278859; Thu, 19 Jan 2023 23:04:38 -0800 (PST) Received: from localhost ([2405:201:6014:dae3:7dbb:8857:7c39:bb2a]) by smtp.gmail.com with ESMTPSA id m1-20020a17090a3f8100b00218f9bd50c7sm715471pjc.50.2023.01.19.23.04.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Jan 2023 23:04:38 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Joanne Koong , David Vernet , Eduard Zingerman Subject: [PATCH bpf-next v4 11/12] selftests/bpf: Add dynptr partial slot overwrite tests Date: Fri, 20 Jan 2023 12:33:54 +0530 Message-Id: <20230120070355.1983560-12-memxor@gmail.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230120070355.1983560-1-memxor@gmail.com> References: <20230120070355.1983560-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2463; i=memxor@gmail.com; h=from:subject; bh=vb2M3d6AP1tJHi9lacIFMdvNjgTaEGGdyWxaqNz5OHI=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjyjzMXtdYoVT+uua2rJKUZ75sLYaxpcQxs+Mg4Z+P 6ikII2eJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY8o8zAAKCRBM4MiGSL8RysOwEA CzsW2KdhXJk+mUEiM7kB9GWRnJBQYx+WrEBj2hmRaHwsuqvD02VAh+C0SMt8O8HD9Udy5lzD2+hJba U5B0bAwciaUMqWYzJiV6wvUrzcFkm8sAof4lTkpnazxMTTwC0VeXhpLMm1WF7dHekUoCz+TNQ9d0iH rismWlQipzLWVSYCq1kqgy0ICxk/KcoVgsaS0LM5klj/EjuTlDahlqm5+XRixg16VeI2AJ/91XvZ1L FTK/Uu2D08n7OfcHqpO3lN72nXZy0LRb++zKUYzMbvhiYQQZl0N91oS5SEmw/5Y8N1jiz540j1zQrT m2T8fRheMvfBwtDVWgQyB0M+JZwt3InPCSAvhqhIBcvrW869J7HFo+7JQegLYEC9SGfEhr1ngz7gky CV9zCLktQ8oFDH0UdiVPDiBn68Wem9K2Zf0VppNfSQUveuiKHrHeOCgZAFP/qDa5o341na/+mQ+a8s t0CjJQlCESgOY2g8sGXFxhQJ5X4xyt/Em1S/ppxHoAhClhvIdT7lp1H4ZQXECbImD1GUQZDFI/OLcF VKYv+dJsLfJ0t8peGOtKqVVco2A3HjS8j3GaYyBeInG0FPpaFvinMQ9hAWWQbrWBRkwY6fxCnW/bOt 2rk54GryLMrW8K9bJJz4zZCyCzxqpK6NjIvCoyldgfryly4sm1LzH1gNn4jw== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Try creating a dynptr, then overwriting second slot with first slot of another dynptr. Then, the first slot of first dynptr should also be invalidated, but without our fix that does not happen. As a consequence, the unfixed case allows passing first dynptr (as the kernel check only checks for slot_type and then first_slot == true). Signed-off-by: Kumar Kartikeya Dwivedi --- .../testing/selftests/bpf/progs/dynptr_fail.c | 66 +++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c index 2d899f2bebb0..1cbec5468879 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_fail.c +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -834,3 +834,69 @@ int dynptr_var_off_overwrite(struct __sk_buff *ctx) ); return 0; } + +SEC("?tc") +__failure __msg("cannot overwrite referenced dynptr") __log_level(2) +int dynptr_partial_slot_invalidate(struct __sk_buff *ctx) +{ + asm volatile ( + "r6 = %[ringbuf] ll; \ + r7 = %[array_map4] ll; \ + r1 = r7; \ + r2 = r10; \ + r2 += -8; \ + r9 = 0; \ + *(u64 *)(r2 + 0) = r9; \ + r3 = r2; \ + r4 = 0; \ + r8 = r2; \ + call %[bpf_map_update_elem]; \ + r1 = r7; \ + r2 = r8; \ + call %[bpf_map_lookup_elem]; \ + if r0 != 0 goto sjmp1; \ + exit; \ + sjmp1: \ + r7 = r0; \ + r1 = r6; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -24; \ + call %[bpf_ringbuf_reserve_dynptr]; \ + *(u64 *)(r10 - 16) = r9; \ + r1 = r7; \ + r2 = 8; \ + r3 = 0; \ + r4 = r10; \ + r4 += -16; \ + call %[bpf_dynptr_from_mem]; \ + r1 = r10; \ + r1 += -512; \ + r2 = 488; \ + r3 = r10; \ + r3 += -24; \ + r4 = 0; \ + r5 = 0; \ + call %[bpf_dynptr_read]; \ + r8 = 1; \ + if r0 != 0 goto sjmp2; \ + r8 = 0; \ + sjmp2: \ + r1 = r10; \ + r1 += -24; \ + r2 = 0; \ + call %[bpf_ringbuf_discard_dynptr]; " + : + : __imm(bpf_map_update_elem), + __imm(bpf_map_lookup_elem), + __imm(bpf_ringbuf_reserve_dynptr), + __imm(bpf_ringbuf_discard_dynptr), + __imm(bpf_dynptr_from_mem), + __imm(bpf_dynptr_read), + __imm_addr(ringbuf), + __imm_addr(array_map4) + : __clobber_all + ); + return 0; +}