From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 5C6963E1209 for ; Fri, 29 May 2026 12:18:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780057084; cv=none; b=CHvJ9uNZpQ5PDN7RfVnKjiSqhrEzpGnuotL4g5E5gO3o9XEtjZJ7naG+E2/0n5nEcx3rlzp2SaNpaYvUZuvAOKg5ysYEBKGLXbAWBcvlH683Bl+X1J7ihNtCLvk+br3tR8l74tyYxepN/1guy2B4DRg5XDmyjdLAjse/ZdG9nH0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780057084; c=relaxed/simple; bh=fdzmWxJGLz9AlLzramjJVHM/pqkHYN7czqaULpgkQ/M=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=UL33tXWr0iNiy0P0uCktXz/Nf1m7PhmfczrEW8ETeGpM4O19/Uba2ifNoArcfvfOOju/rB5+UUAUJqa/14SmS51kpW5Tx7Lwp5NtP64rA6TTVQ1NQX+FZRbsABJKmkJdUqJpJ4HJVNtiMaveo7AMM6VYJxkrvpDH7sc8gNgfMIY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tabba.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=X5/5sNO5; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tabba.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="X5/5sNO5" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-49041d39887so56636425e9.2 for ; Fri, 29 May 2026 05:18:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780057079; x=1780661879; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=OefBi9Ucl75C903M9JEhzfF/8vc9lZTl6eXKcY7A1xo=; b=X5/5sNO5wpYD6YVjbaNq4JGyOSRFvMIpKlP4tKmoYKoqyXVOkmTbqfwQ0XRAQRAOt/ mV7l9z1vwTElRBsMzirsgXdP6/FXKJPwpdVx4BVBwnnOMiuLggMaJf60xGUwPoh/t0VG /99Nru0Pxl7EROWfL5FfLm343oJlwhpSgsg6s2dsvamiytsq2Pa8L63vwozW4ObsiBBY F1w6UOK6a6NM8YXISHZvAfV4tUpDm1rZk4xWGOQ28zeipX2dBfJUeub62VrA+8N3WlC+ NYol8srCimec4REJMT8Wsa2SG9U+PUAkCTupvXsna4cIsd+bkXLg5jUojfIFY1t91xwj 4E4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780057079; x=1780661879; h=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; bh=OefBi9Ucl75C903M9JEhzfF/8vc9lZTl6eXKcY7A1xo=; b=HyJVISDISO3UmCuOrH0xqh9N0HPcmtT0294j1BQ7onqHGTXVF972ZKdjqRISnhIVPM kBe35+Jr9wdka4SshsTVI0ve086Y1Qhdo3zKfmvfsTqEUeAuXbEMew0q2GwzJgobOTBk nnjKH5H3USBqk2aZkDSJWP8EhoUxOwjKdPje2AKEVikXnU5PzH7ElNG5k0W7b/3lRLbC fh9hOzMHSpfPiNV2KGJFYmBMpoXvdL15/o08GhRTrVYw7zhxT9/EYcN1lYfZMNlcmB8Q 3+mxxuzBr+P++Zoa/9ox9tKtYkuuBq2L0xANyFBJxi0v9R0EG9BSURDFZm7O4yeRH4o+ wSaQ== X-Forwarded-Encrypted: i=1; AFNElJ/V8t4mKrrgf5IfC0WrOluKZFYDlR9rWFqG0MIqRIPyeUEdKxRGHh91qrNb/GT1HU6Q+TTW0E2pjPbkEmE=@vger.kernel.org X-Gm-Message-State: AOJu0YxqrUj8rAOrLt9PKrucVj0jrtmAXhDz1UaDOS4XLEAh6zK0Nmk/ OMnaS1SM7uVKAeWOZFNSiPgY450wS4J+phb959nU7h4QKaOAJvA1CUwcVDfbbDr4w/InWlMGc1H iXA== X-Received: from wmbgx17.prod.google.com ([2002:a05:600c:8591:b0:490:11e5:b5aa]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:6008:b0:490:44eb:c1e0 with SMTP id 5b1f17b1804b1-4909c0ac911mr37129365e9.21.1780057078508; Fri, 29 May 2026 05:17:58 -0700 (PDT) Date: Fri, 29 May 2026 13:17:53 +0100 In-Reply-To: <20260529121755.2923500-1-tabba@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260529121755.2923500-1-tabba@google.com> X-Mailer: git-send-email 2.54.0.929.g9b7fa37559-goog Message-ID: <20260529121755.2923500-2-tabba@google.com> Subject: [PATCH v2 1/3] KVM: arm64: Free hyp-share tracking node when share hypercall fails From: tabba@google.com To: Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Quentin Perret , Vincent Donnefort Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" share_pfn_hyp() inserts a tracking node into hyp_shared_pfns and then invokes __pkvm_host_share_hyp. If the hypercall rejects the share (page-state mismatch at EL2), the node stays in the tree with refcount 1: a phantom share that leaks the allocation and that a later unshare will trust. Erase the node and free it on hypercall failure. Fixes: a83e2191b7f1 ("KVM: arm64: pkvm: Refcount the pages shared with EL2") Reported-by: Sashiko (local):gemini-3.1-pro Suggested-by: Vincent Donnefort Signed-off-by: Fuad Tabba --- arch/arm64/kvm/mmu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 4da9281312eb..4a928fb003ff 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -501,6 +501,10 @@ static int share_pfn_hyp(u64 pfn) rb_link_node(&this->node, parent, node); rb_insert_color(&this->node, &hyp_shared_pfns); ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn); + if (ret) { + rb_erase(&this->node, &hyp_shared_pfns); + kfree(this); + } unlock: mutex_unlock(&hyp_shared_pfns_lock); -- 2.54.0.929.g9b7fa37559-goog