From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 36DE6277026; Sat, 17 Oct 2026 16:55:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792256129; cv=none; b=G0Y5iwlEtyHYad8RdGT5kszZ5y3+MqBs3eJnmwfr2tLznwwZdU24czieIdBCuX3vAtr8ye+ZZ6DVSTNGdlX0RTSgRlASO1q1JSSGUBTvALOzkeYWx30f1tDBoEuNlewSntXvLTlsGHZWvlepUS08KsDB+Jr2kThusI5N8igjZ7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792256129; c=relaxed/simple; bh=ftBST20dwLuhKdw9+4uIAIWNuqSMEtQ11qDwynlGKek=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KJGVKH1M+g6f5LoDwNp1V3XD60xP1z6MCvW+QRyHchf2JTT57maaX3JrFx7YoR6NPNs11MJfdrk11BDeFo4gtuKGRs0ZC/C8KC7/d+/lCZlkfVEzFbeJIZTeJKuMEXtmc5cE2k4cIVWdsF8TX49bcjrzaTQK2CryAUEaxbOm3SE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VDk+p/nu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="VDk+p/nu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D7191F000C4; Sat, 17 Oct 2026 16:55:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792256128; bh=6bcMd0+7RonZJhWEl999BKhWYzCPzbR8r4gesd9i27Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VDk+p/nu+D7m27eOyXdQ/ADpc13nwS64n8aszbhnTcDQcZH7+SptUlLdRAX7rqscR fBMCstVegiEPMsSmqENu6ovGYqCYjLoFCWKn+pOsIMbJ+MAYvcn0NEMfLMlP1QJqLx gK3i9u298wExPsXtEG2wPa2EW9kdZOEJTuXkM/NI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xie Bo , Anup Patel , Sasha Levin Subject: [PATCH 6.6 0134/1674] RISC-V: KVM: Serialize IMSIC attributes with vCPU migration Date: Sat, 17 Oct 2026 17:40:06 +0200 Message-ID: <20261017160434.600425088@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xie Bo [ Upstream commit 8ae12ccaec6ec74945d8c1ef39f2c1b8df779abc ] KVM device ioctls are not serialized against KVM_RUN. As a result, kvm_riscv_aia_imsic_rw_attr() can snapshot the physical CPU and HGEI of an IMSIC VS-file before a concurrent vCPU migration releases it. The HGEI can then be allocated to another vCPU before imsic_vsfile_rw() uses the stale tuple. A GET or SET attribute may consequently access the new owner's interrupt file. Serialize the entire IMSIC attribute operation with the target vCPU mutex. This prevents the VS-file from being migrated and recycled until the attribute access completes. Acquire the mutex killably so that the device ioctl remains interruptible while waiting for KVM_RUN to finish. Fixes: db8b7e97d613 ("RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC") Cc: stable@vger.kernel.org Signed-off-by: Xie Bo Reviewed-by: Anup Patel Link: https://lore.kernel.org/r/20260810-imsic-attr-race-v2-1-00ed95ad321e@ultrarisc.com Signed-off-by: Anup Patel Signed-off-by: Sasha Levin --- arch/riscv/kvm/aia_imsic.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c index 562890ac5d0b0..22782b009e370 100644 --- a/arch/riscv/kvm/aia_imsic.c +++ b/arch/riscv/kvm/aia_imsic.c @@ -895,9 +895,14 @@ int kvm_riscv_aia_imsic_rw_attr(struct kvm *kvm, unsigned long type, if (!vcpu) return -ENODEV; + if (mutex_lock_killable(&vcpu->mutex)) + return -EINTR; + imsic = vcpu->arch.aia_context.imsic_state; - if (!imsic) - return -ENODEV; + if (!imsic) { + rc = -ENODEV; + goto out_unlock; + } isel = KVM_DEV_RISCV_AIA_IMSIC_GET_ISEL(type); read_lock_irqsave(&imsic->vsfile_lock, flags); @@ -921,6 +926,8 @@ int kvm_riscv_aia_imsic_rw_attr(struct kvm *kvm, unsigned long type, rc = imsic_vsfile_rw(vsfile_hgei, vsfile_cpu, imsic->nr_eix, isel, write, val); +out_unlock: + mutex_unlock(&vcpu->mutex); return rc; } -- 2.53.0