From patchwork Mon Oct 21 01:40:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13843478 X-Patchwork-Delegate: bpf@iogearbox.net Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 662EADDA8 for ; Mon, 21 Oct 2024 01:28:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729474088; cv=none; b=Hi5dIGkjGFQAlHA4a2F/tn9zSzKMFZkuOhbOTnryDK+Xgi8ohj29XgD4353aSkmkumOqJXMCLetY3sHnTnQ/NU78D5GdIKApJqlpx6twXhoQqJ776F8coGz1D2pm4AQ/SPtAkQDefLqVjNIdk5XQU7x5olN9xirt5q8af6Mz1Xw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729474088; c=relaxed/simple; bh=/Rdx6qk/dV4KoO4bhE36gfZxFheqmBxWtvriac3vtrA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Ksr5dc7OCv065R06wOEsWQLGvtCEeG5lrOHRMUCrRQQR15cAwKnqdfxdzgFcnuQZaUByAfIWgmhIw6k+HZ7MLt2ejAI3I70nP51pmh4vkx+ppj77hOOApc5GPhxBowv818eQVae/G6ZXDrj8CRxlB7naxJ97NqfVKFkgSgTyPS8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4XWyNd5jVxz4f3jkk for ; Mon, 21 Oct 2024 09:27:45 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 0A8CF1A0568 for ; Mon, 21 Oct 2024 09:27:58 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgCXysYXrhVnot2wEg--.32425S9; Mon, 21 Oct 2024 09:27:57 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org Cc: Martin KaFai Lau , Alexei Starovoitov , Andrii Nakryiko , Eduard Zingerman , Song Liu , Hao Luo , Yonghong Song , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , Yafang Shao , houtao1@huawei.com, xukuohai@huawei.com Subject: [PATCH bpf v2 5/7] bpf: Check the validity of nr_words in bpf_iter_bits_new() Date: Mon, 21 Oct 2024 09:40:02 +0800 Message-Id: <20241021014004.1647816-6-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20241021014004.1647816-1-houtao@huaweicloud.com> References: <20241021014004.1647816-1-houtao@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgCXysYXrhVnot2wEg--.32425S9 X-Coremail-Antispam: 1UD129KBjvdXoW7JFW3urW5tw4fJw4Dtr4Utwb_yoWkuFX_GF Wjqa4kKrs8uFs3tr1qyr1SvrW5tw18KF4rCw4UJrZ7ur1rA3Z5JF4rtryDZa97Wr1DAFsx Jws3XFWq9r1a9jkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbqAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7IE14v26r126s 0DM28IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0c7CEw4AK67xG Y2AK021l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14 v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAF wI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2 WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7 AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02 F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_Wr ylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7Cj xVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxV WUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxU F9NVUUUUU X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao Check the validity of nr_words in bpf_iter_bits_new(). Without this check, when multiplication overflow occurs for nr_bits (e.g., when nr_words = 0x0400-0001, nr_bits becomes 64), stack corruption may occur due to bpf_probe_read_kernel_common(..., nr_bytes = 0x2000-0008). Fix it by limiting the max value of nr_words to 512. Fixes: 4665415975b0 ("bpf: Add bits iterator") Signed-off-by: Hou Tao Acked-by: Jiri Olsa --- kernel/bpf/helpers.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 62349e206a29..c147f75e1b48 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2851,6 +2851,8 @@ struct bpf_iter_bits { __u64 __opaque[2]; } __aligned(8); +#define BITS_ITER_NR_WORDS_MAX 512 + struct bpf_iter_bits_kern { union { unsigned long *bits; @@ -2892,6 +2894,8 @@ bpf_iter_bits_new(struct bpf_iter_bits *it, const u64 *unsafe_ptr__ign, u32 nr_w if (!unsafe_ptr__ign || !nr_words) return -EINVAL; + if (nr_words > BITS_ITER_NR_WORDS_MAX) + return -E2BIG; /* Optimization for u64 mask */ if (nr_bits == 64) {