From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 591FC44C670 for ; Wed, 19 Aug 2026 10:28:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787135311; cv=none; b=WbyHigVla9GKQnbz991KBisnKUxQPQgB8Uqi3dVDfGehHpE0hSLwavfNw2ZL2U13Xu+DTy9nmdXmpeJRw7ZBK6nzwK1Q7jaQEaVJJp/7EJj+/rBY7ffDKFkTTn6uSMRT7/7uTlwc6qUQAEBQmrp6J95xFUiFF3e+nwuGhSEQwt4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787135311; c=relaxed/simple; bh=gt4LUz6h5wdD5n/G/j7Qa+IcB6A6stflUNl5aSZem7k=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=n1ZJQv7BdBN14a06L8F0wAkgozqfvGww079rzkABFAknt6HzTcbUYrkq2BuVSh1OyutgluKHNwk7pIVsYIvuirUDgisP/kL/tzXhLr0PTbWdCihA43XxbyOSoXkvYi+uylC2AIGOvvqEfEgCbIQaE6axSFXdtpF4IkEtf7aW9kg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=FNX+dtOP; arc=none smtp.client-ip=91.218.175.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="FNX+dtOP" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=gt4LUz6h5wdD5n/G/j7Qa+IcB6A6stflUNl5aSZem7k=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1787135304; v=1; x=1787740104; b=FNX+dtOP+BMnAoZhYheV5rHOmQpLGCMD7bFh0Y93NzumSAJC5xEDiumMv4QHlzPC96jWB6Uu 5qJzRkNhMvCu4LLTBcntTd1U2VoHmzJy1LTzIxbC0+YXj27FajBiR3yBsjfHW1Pg28NzV92qsPt gjDxVs2r6iYd88uVarg7NGyo= X-Envelope-To: linux-kernel@vger.kernel.org Received: from claudy.lan (37.156.72.212) by smtp.migadu.com with ESMTPS id 1b7461c5e495a37b; Wed, 19 Aug 2026 10:28:24 +0000 X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton Cc: Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Will Deacon , Sascha Bischoff , Sebastian Ene , Eric Auger , Fuad Tabba , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/4] Revert "KVM: arm64: vgic-its: Don't save collections the table cannot hold" Date: Wed, 19 Aug 2026 11:28:07 +0100 Message-Id: <20260819102809.310708-3-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20260819102809.310708-1-fuad.tabba@linux.dev> References: <20260819102809.310708-1-fuad.tabba@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This reverts commit 9b10fb74e4b661543d188701bd4d024fc5c18f58. Freeing the collections when GITS_BASER changes removes the state this check rejected: vgic_its_cmd_handle_mapi(), vgic_its_cmd_handle_mapc() and vgic_its_restore_cte() all validate the ID against the current table before allocating, and the table can no longer change under the list. What remains is a collection whose entry is not backed by a memslot, which the write fails on anyway, so the check costs a save userspace should be able to issue reliably and buys nothing. The reverted commit credited the check with bounding the walk as well. It stays bounded without it: collection IDs are unique and each is below the table's capacity, so the list cannot be longer than the table. Suggested-by: Marc Zyngier Link: https://lore.kernel.org/all/87ecg9owwa.wl-maz@kernel.org/ Signed-off-by: Fuad Tabba --- arch/arm64/kvm/vgic/vgic-its.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 3339d9977af27..cc6ea5c3409ae 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -2535,9 +2535,6 @@ static int vgic_its_save_collection_table(struct vgic_its *its) max_size = GITS_BASER_NR_PAGES(baser) * SZ_64K; list_for_each_entry(collection, &its->collection_list, coll_list) { - if (!vgic_its_check_id(its, baser, collection->collection_id, NULL)) - return -EINVAL; - ret = vgic_its_save_cte(its, collection, gpa); if (ret) return ret; -- 2.39.5