From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3A06F383329; Fri, 22 May 2026 20:45:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779482721; cv=none; b=n4I+Mon/O4iLtCF/C224WyYpilPRsqprTENpxkJnu11u//Q3oNdmJ+IeHh0O3ZiMrJhnQBeLPa/NrcTKMj1DtNEJME9IyTvar/VW4bBryI4pa4WZWWq5BgYUuvVnYkCH4G4hJvDbLAgzlfOUJAIwlpMyRSMvte03hyU/IU37YV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779482721; c=relaxed/simple; bh=VjzCzd1nFC0V+VspHRSm811yDhk2SVg8NJFOEp8BNQU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=rJLZD6ZAhc56VwxCxFH6i7Zidu6Y5NFsVg16V6Gap87G4qN5emkqEga+XU8/tkuiTLWruRIF6VVVviaulVkdu8SBGeLH5jqBZAAyF16oF5wTcyFi4ym2XEO53X2aZeJESgFZXGnr2A/ZxmXBMXxVI1ampJYLAJ/0ZT1TPJXTT3Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uRFyQShk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uRFyQShk" Received: by smtp.kernel.org (Postfix) with ESMTPS id F13CAC2BCC6; Fri, 22 May 2026 20:45:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779482721; bh=VjzCzd1nFC0V+VspHRSm811yDhk2SVg8NJFOEp8BNQU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=uRFyQShklzep8NxZ2OAADVrGtvknLWCj6uIgDGig54xBvGhyhrJp209JlmBmVLms7 IMISFyZYvoq+kRQutKSH+180AeZEAQCev3R5K/LhTVjJuEVya2UcJeT8bICwbILgvb 6UdPkVYaCpc/Ckik5lg9PqDlHxywzcd5Mpl7Mf9cA/5CnOS8yjlX/QB9H6iKtoUBIR qnMs/Dbf7YaHhPxbbjh2YoxoRQLIU0XcrKjQ74fAdTs+lQciDLwbGTnGaT6cWWSOs/ fQ1BsFXnj0APT1qgIjDHCmbJwIqR+El6AEBfkrqFEmk9hLaR5vaLTm6s6qb/ukIW+j s+LxmmLfLvQoQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id E14ECCD5BB7; Fri, 22 May 2026 20:45:20 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Fri, 22 May 2026 13:45:09 -0700 Subject: [PATCH 3/3] KVM: guest_memfd: Handle errors from xa_store_range() when binding Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260522-fix-sev-gmem-post-populate-v1-3-9fc8d6437b65@google.com> References: <20260522-fix-sev-gmem-post-populate-v1-0-9fc8d6437b65@google.com> In-Reply-To: <20260522-fix-sev-gmem-post-populate-v1-0-9fc8d6437b65@google.com> To: Sean Christopherson , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Kiryl Shutsemau , Rick Edgecombe , Vishal Annapurve , Yan Zhao , Michael Roth , Isaku Yamahata , Chao Peng , Xiaoyao Li , Zongyao Chen Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, Yu Zhang , Fuad Tabba , Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1779482720; l=1599; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=ppXZ9n7Px9sWPfCeSXJF2Jv5JKohLthkttbhOhgzju8=; b=umbtB2eulJGonqQIEnj0i8tfpFY/JDZfh8iROfUqls2ag7+sahhvKQjHe1YuUZhxnsbzOG+Pg BRTn7AR84LPBWKSpCfIJoEkcbhsFvmOeRkHiyYN2FQYa0Jjf3STwOTj X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com From: Ackerley Tng Unhandled errors from xa_store_range() means kvm_gmem_bind() might falsely reporting success, leading to false assumptions in guest_memfd's lifecycle later. Handle these errors by checking and returning the error to the userspace. Fixes: a7800aa80ea4d ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory") Signed-off-by: Ackerley Tng --- virt/kvm/guest_memfd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index d203135969d13..104f0f3d6a0b3 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -648,6 +648,7 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_slot *slot, struct inode *inode; struct file *file; int r = -EINVAL; + void *result; BUILD_BUG_ON(sizeof(gfn_t) != sizeof(slot->gmem.pgoff)); @@ -688,7 +689,7 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_slot *slot, if (kvm_gmem_supports_mmap(inode)) slot->flags |= KVM_MEMSLOT_GMEM_ONLY; - xa_store_range(&f->bindings, start, end - 1, slot, GFP_KERNEL); + result = xa_store_range(&f->bindings, start, end - 1, slot, GFP_KERNEL); filemap_invalidate_unlock(inode->i_mapping); /* @@ -696,7 +697,7 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_slot *slot, * not the other way 'round. Active bindings are invalidated if the * file is closed before memslots are destroyed. */ - r = 0; + r = xa_is_err(result) ? xa_err(result) : 0; err: fput(file); return r; -- 2.54.0.794.g4f17f83d09-goog