From nobody Sun May 24 22:42:29 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 61C63242D9D; Thu, 21 May 2026 00:57:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779325021; cv=none; b=EUa1D3cYKT5/QdsZtwLIyZUeC1ZhnmsfI78prAUlbW19blKs098bygwn8VK9Pgv2DC4buSV5JnNd3tvGldnQLa9RVJWvostjX1enNyZEin3p7plH2oILrbbS9dzOHWq2ZU9aFYJG7QiskNQBdBO4M2xEVhVBemEsvkEspoEaFHs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779325021; c=relaxed/simple; bh=lpA43hPdk2MRnmPzUy57WOwWHngWFQqxKv4IWLsTT6k=; h=Date:From:To:Subject:Cc:MIME-Version:Message-ID:Content-Type; b=ifu6AhwPVYCvqltZ0UnW896Oq1bCPW4ykP1VmBmeiVC7RqE+srY0GGthDJ0hgtX7X3JG9RlWBV71aR68Gy0PT0rYZcabYcKW8LaCzSXT4MaKajiMOWpENvYtuym/R/E7xppqiIp9jJVqf2KX8rtqo0QHmTirRUOFU4WLDrioEDA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=k93teupO; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=17Mgeal3; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="k93teupO"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="17Mgeal3" Date: Thu, 21 May 2026 00:56:56 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1779325018; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=qlWXEgKmj6PVBVrltp+UKnAHPfMiWO25pv8uzd6G1e0=; b=k93teupOLQU1P+zF4GJKiUEI5CsJsVdXcUrUKzuxZc3di1aNTsEulqZSxFNg4W4OxuYApd EmzjjQwb81Ww+veerAB0l8NNRJRzVeqRUexNwVAemE1dzIaBzTqe6J+2fRFKqC6C8iuRQH gnsVM524p5aG76JE/WarbXiiCCQISiuXugcgZX1wcAAITYcxuM+se1Vv2z96kL63c4fbqv Xo7vNEN8VWuYZC8Iw+zYAlDUrrNy9U3jmpdP1C3KZ8ps84A6lUg8TYf8fIuHdu9sC7+k5A CZnHuE0zmf07GZFg3JJzYbnaDfrmfRcFd25ZFuDI5CSu6kmbMdy+EjS08PLPzA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1779325018; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=qlWXEgKmj6PVBVrltp+UKnAHPfMiWO25pv8uzd6G1e0=; b=17Mgeal3rUnR3LBs/Cq3iatPFbtoX7xWyDI2L/QHIBNOppIGvBCtxnY6fb7Hvx5eU4dRWK fpXOUMpJhmt02/Bg== From: tip-bot2 for Carlos =?utf-8?q?L=C3=B3pez?= Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/sev] virt: sev-guest: Explicitly leak pages in unknown state Cc: clopez@suse.de, "Borislav Petkov (AMD)" , stable@kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <177932501671.711.1447981525705312867.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/sev branch of tip: Commit-ID: f64c0a7bcb6c79dcb2bde792d84a75644f38ee04 Gitweb: https://git.kernel.org/tip/f64c0a7bcb6c79dcb2bde792d84a75644= f38ee04 Author: Carlos L=C3=B3pez AuthorDate: Tue, 12 May 2026 12:00:42 +02:00 Committer: Borislav Petkov (AMD) CommitterDate: Wed, 20 May 2026 16:36:19 -07:00 virt: sev-guest: Explicitly leak pages in unknown state When set_memory_{encrypted,decrypted}() fail, the user cannot know at which point the function failed, meaning that the pages are left in an unknown st= ate from the point of view of the caller. Since the pages may be left in an unencrypted state, they are not suitable = for general use, and cannot be returned safely to the buddy allocator. Avoid the issue by never freeing the pages, and then do the proper accounting by call= ing snp_leak_pages(). Fixes: 3e385c0d6ce8 ("virt: sev-guest: Move SNP Guest Request data pages ha= ndling under snp_cmd_mutex") Signed-off-by: Carlos L=C3=B3pez Signed-off-by: Borislav Petkov (AMD) Cc: stable@kernel.org --- drivers/virt/coco/sev-guest/sev-guest.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/se= v-guest/sev-guest.c index 910a1de..d186ae5 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -176,6 +176,7 @@ static int get_ext_report(struct snp_guest_dev *snp_dev= , struct snp_guest_reques struct snp_guest_req req =3D {}; int ret, npages =3D 0, resp_len; sockptr_t certs_address; + u64 pfn; =20 if (sockptr_is_null(io->req_data) || sockptr_is_null(io->resp_data)) return -EINVAL; @@ -215,10 +216,11 @@ static int get_ext_report(struct snp_guest_dev *snp_d= ev, struct snp_guest_reques if (!req.certs_data) return -ENOMEM; =20 + pfn =3D PHYS_PFN(virt_to_phys(req.certs_data)); ret =3D set_memory_decrypted((unsigned long)req.certs_data, npages); if (ret) { pr_err("failed to mark page shared, ret=3D%d\n", ret); - free_pages_exact(req.certs_data, npages << PAGE_SHIFT); + snp_leak_pages(pfn, npages); return -EFAULT; } =20 @@ -272,10 +274,12 @@ e_free: kfree(report_resp); e_free_data: if (npages) { - if (set_memory_encrypted((unsigned long)req.certs_data, npages)) + if (set_memory_encrypted((unsigned long)req.certs_data, npages)) { WARN_ONCE(ret, "failed to restore encryption mask (leak it)\n"); - else + snp_leak_pages(pfn, npages); + } else { free_pages_exact(req.certs_data, npages << PAGE_SHIFT); + } } return ret; }