From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A1448C55172 for ; Fri, 31 Jul 2026 14:36:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5WScly32cO/pWys+NwDAhbqd6QITQjPoTI8up8SEAyk=; b=wCTww7+pLH12QMDceUMnpX0U87 wq6U33dCvlUAfTlTvv9ZmLabDNsPsV8O3mlVqaZcfaiTfiZdTXe00sm6PTwmaJhDi3NcoOuOjgyTo JeW5Wz5qVVuJdph1DTedY+JMMJoUWV0DqP+THWk6EMNZUjyDm1tI386B1QLKTY6QgJ1kUe82n2gH9 NSDP4pHn0doFimi67Lgd5+WlGyq0jdc32rVO/GDNA/kgo4fCpn6vHK+mJFQWbnLiqf9+twoXSBGV/ v2tLtmUbwxkOLC0dw7yo2SqMuqeuXsTL+tsqkBgJBR+Plhm/PAR8nwW6HO2Q/jlhJOxvBn/X4ApnI PJZBTi/Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wpoLa-0000000CjjT-1Lcz; Fri, 31 Jul 2026 14:36:26 +0000 Received: from mail-ed1-x547.google.com ([2a00:1450:4864:20::547]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wpoLP-0000000CjZC-3YuB for linux-arm-kernel@lists.infradead.org; Fri, 31 Jul 2026 14:36:20 +0000 Received: by mail-ed1-x547.google.com with SMTP id 4fb4d7f45d1cf-69c033344cdso1038469a12.2 for ; Fri, 31 Jul 2026 07:36:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785508572; x=1786113372; darn=lists.infradead.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=5WScly32cO/pWys+NwDAhbqd6QITQjPoTI8up8SEAyk=; b=HQGC6fm+nhM8Lmn+fTWu+4cfmFhvPWqiYl4opR83oznn1qN1m+iRG86jYy3RY/ld/q Uks3DkOlEAMcNiEehinNM5FdykOJ8z7Y0AQ2ijVk5vesXY/ob7J865rptoDkOOPWqq5v bIL+3vMdNV5RXTqIsWFavjvywSGyePosRMr4LKPIc7ppH/6bbE9gBOnnULUibzC/ulOQ AdZR2/Pvo6LtCGJyEe7z9A5qqE6CYO4ON8Sr9few2dwGxB3F9+YzfEvE9Fhr/NtEilIW 12hDOgadEy1SkVAHOL9ND792znOqSF4EsjPrl4dHzvH5VWrm/L2qGBxB23ct9C8CqNnP e4VQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785508572; x=1786113372; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=5WScly32cO/pWys+NwDAhbqd6QITQjPoTI8up8SEAyk=; b=cSf2bQZ297XISTn7m7Y4DnTIbxINIT2mRHtROw3a0PAulRJYIHFbByQ2Hb3ie4dfSQ p6fjOVfErb8iV26GorFrq+FhP4/5Brpscoc+3MEdoV07sNWrzGkJKD6QO8hnqtbdU5Fj GmwSDEWdW3VMz5x7hAWP+joeUDjUtIpJXfzYZfRfssG/nxL19zybySZCoBKuNciAMDpy +WdPP/c2ttArQPt4hpoBar5f4ekCv/2bYblcZDW1eMhgMFOWLiC/QlLdxO77LskaLMPv xs7ESKYxCxcUuGah0HWdYke76+5BVy5UNMwRfKmBvSgy0PpB43Ual3QmMTi+2fpCzYBq dkKw== X-Forwarded-Encrypted: i=1; AHgh+RrKemdnu8hWCqyLEZu6u91FkkkgfS+Fm2lxPaxfqWI7Ur2bIHiNwYzSVV7EDwJxGkyZx24c/XsilTVz2T+owRqL@lists.infradead.org X-Gm-Message-State: AOJu0YxXffZ6wPA87+aRbldJdcOtH3Cq78JWKVvWFRMn6eA1oJqRKoZ4 xMbiO3VA6bSnfFBCzqPrepVl0H55QTJTwLFSumqCH3/uBzXdI/d+Kd3upNMisqZhdheVSPlhu5z EIjSgN8sumxw2o9gzM8L07Q== X-Received: from wmjx19.prod.google.com ([2002:a05:600c:21d3:b0:493:c42c:7e97]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:5046:b0:6a0:9465:3e0c with SMTP id 4fb4d7f45d1cf-6a098d1bc48mr1448179a12.32.1785508572350; Fri, 31 Jul 2026 07:36:12 -0700 (PDT) Date: Fri, 31 Jul 2026 15:35:40 +0100 In-Reply-To: <20260731143541.956291-1-vdonnefort@google.com> Mime-Version: 1.0 References: <20260731143541.956291-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.508.g3f0d502094-goog Message-ID: <20260731143541.956291-17-vdonnefort@google.com> Subject: [PATCH v4 16/17] KVM: arm64: Reject hyp trace descriptors with fewer than 3 pages From: Vincent Donnefort To: maz@kernel.org, oupton@kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, kernel-team@android.com, fuad.tabba@linux.dev, qperret@google.com, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260731_073615_960226_6F17CEAE X-CRM114-Status: UNSURE ( 9.28 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org A trace descriptor with 0 nr_page_va allocates a 0-size bpages backing region, which makes the ring buffer appear unloaded. Reject descriptors with nr_page_va < 3 in hyp_trace_desc_is_valid() as this is in any case the lower-limit for simple_ring_buffer. Tested-by: Fuad Tabba Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp/nvhe/trace.c b/arch/arm64/kvm/hyp/nvhe/trace.c index 6e716295247a..96afa3d6de2f 100644 --- a/arch/arm64/kvm/hyp/nvhe/trace.c +++ b/arch/arm64/kvm/hyp/nvhe/trace.c @@ -189,6 +189,10 @@ static bool hyp_trace_desc_is_valid(struct hyp_trace_desc *desc, size_t desc_siz if ((void *)rb_desc + struct_size(rb_desc, page_va, 0) > desc_end) return false; + /* simple_ring_buffer_init_mm() expects at least 3 pages */ + if (rb_desc->nr_page_va < 3) + return false; + /* Overflow desc? */ if ((void *)rb_desc + struct_size(rb_desc, page_va, rb_desc->nr_page_va) > desc_end) return false; -- 2.55.0.508.g3f0d502094-goog