From patchwork Mon Mar 2 13:27:03 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiakai Xu X-Patchwork-Id: 2203396 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=hAZef7B2; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=desiato.20200630 header.b=moKm62ty; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org; envelope-from=kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=patchwork.ozlabs.org) Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4fPfqj3n5mz1xwp for ; Tue, 03 Mar 2026 00:27:29 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=HGKcbT7CsUC279GV/Ju5YfHK7LNszT+aDVgYr4/jEHg=; b=hAZef7B2jbcmjy 9JKOtYtZaCvQEp9/lI8O1ANtrGtmFf2R3WfsKwqolL6fdDxIUaVTqncQOyY85cbR2uwb+SojfRQ3Q Kd2HTIo223Fip8VTHsyX1khUNEnu/kFmytotv9iIMWIxrjdm3cS2zkqiD74PqUUCInMsAYISN6Abb S3phPeS+8y0OI4PVFZDeBB48IvZFzDPmBKwo0pmWwh64Aro4kSGyLHaHJ4mzw+P97sv4HT1P4l5H5 fKAXOloMLfEROD67y34p5XhmShRef7cwt0usXuFplhIRyT+0tkrsutsDw7JsqKnbmztZ8cgoR0k80 4ulV5bFhCkWtIna6ChQw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vx3J1-0000000D6H0-2ykU; Mon, 02 Mar 2026 13:27:27 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vx3J0-0000000D6GV-1Vzw; Mon, 02 Mar 2026 13:27:26 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=RuZFEnl9j78powhTNWsrxd/rXdyRxdzz6mO/eVLrOq4=; b=moKm62tyqw/w178p8wbUO3CMWB 7v+21OZ3mZaAnHFYio2uYB+Vrr0mX0HNATNeQEfD82GwigwUfr+LvskZ82kghDbj8f6Plbd3uFF/f EPn+LwG0DU7nssTBruuzTAU0cGxYWYonFKAezQgiLZoC068BanTJALqjHBLd83HgPkoLej6Hg8Hlb Sv77gZgvIx4cXK07KaCXmt+G/t1AboW4LbsoDndCR/TbiBlIm2LlgNBBkzSn8br0/FFmcvucCGCQJ J+63looI4ViUi8t5gHrs/Z+Bv2eb9LyW+fv4+W+OAWvWPwhdTJhh3pAOcw+MByrc/vWS7wNwbhEQt RRniTyhQ==; Received: from smtp21.cstnet.cn ([159.226.251.21] helo=cstnet.cn) by desiato.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vx3Iv-000000009rs-0z7z; Mon, 02 Mar 2026 13:27:24 +0000 Received: from fric.. (unknown [210.73.43.101]) by APP-01 (Coremail) with SMTP id qwCowABXw24pkKVpxM0bCQ--.814S2; Mon, 02 Mar 2026 21:27:05 +0800 (CST) From: Jiakai Xu To: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org Cc: Alexandre Ghiti , Albert Ou , Palmer Dabbelt , Paul Walmsley , Atish Patra , Anup Patel , Jiakai Xu , Jiakai Xu Subject: [PATCH v3] RISC-V: KVM: Fix use-after-free in kvm_riscv_aia_aplic_has_attr() Date: Mon, 2 Mar 2026 13:27:03 +0000 Message-Id: <20260302132703.1721415-1-xujiakai2025@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-CM-TRANSID: qwCowABXw24pkKVpxM0bCQ--.814S2 X-Coremail-Antispam: 1UD129KBjvJXoWxWF4fGF45WF4DGrWrGF1rJFb_yoWrJw1xpF WrCFyDArW5Gw1xGrZxtw1kXw429r4Yk3W3GrWUWrWI9rsxtrWxtr9a9ryjvr4YyFW8Jasa qF4Ykas5ur45JF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBE14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVW8JVWxJw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAG YxC7M4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14v26r1q6r43MxkIecxEwVAFwV W5GwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMI IF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUVc_fUUUUU = X-Originating-IP: [210.73.43.101] X-CM-SenderInfo: 50xmxthndljiysv6x2xfdvhtffof0/1tbiDAcOCWmljDcJNwAAsF X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260302_132721_782992_680D56BF X-CRM114-Status: GOOD ( 11.67 ) X-Spam-Score: -0.2 (/) X-Spam-Report: Spam detection software, running on the system "desiato.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Fuzzer reports a KASAN use-after-free bug triggered by a race between KVM_HAS_DEVICE_ATTR and KVM_SET_DEVICE_ATTR ioctls on the AIA device. The root cause is that aia_has_attr() invokes kvm_riscv_aia_ [...] Content analysis details: (-0.2 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [159.226.251.21 listed in list.dnswl.org] 0.4 RCVD_IN_VALIDITY_CERTIFIED_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [159.226.251.21 listed in sa-trusted.bondedsender.org] 0.7 RCVD_IN_VALIDITY_SAFE_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [159.226.251.21 listed in sa-accredit.habeas.com] 1.0 RCVD_IN_VALIDITY_RPBL_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [159.226.251.21 listed in bl.score.senderscore.com] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: kvm-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kvm-riscv" Errors-To: kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org Fuzzer reports a KASAN use-after-free bug triggered by a race between KVM_HAS_DEVICE_ATTR and KVM_SET_DEVICE_ATTR ioctls on the AIA device. The root cause is that aia_has_attr() invokes kvm_riscv_aia_aplic_has_attr() without holding dev->kvm->lock, while a concurrent aia_set_attr() may call aia_init() under that lock. When aia_init() fails after kvm_riscv_aia_aplic_init() has succeeded, it calls kvm_riscv_aia_aplic_cleanup() in its fail_cleanup_imsics path, which frees both aplic_state and aplic_state->irqs. The concurrent has_attr path can then dereference the freed aplic->irqs in aplic_read_pending(): irqd = &aplic->irqs[irq]; /* UAF here */ KASAN report: BUG: KASAN: slab-use-after-free in aplic_read_pending arch/riscv/kvm/aia_aplic.c:119 [inline] BUG: KASAN: slab-use-after-free in aplic_read_pending_word arch/riscv/kvm/aia_aplic.c:351 [inline] BUG: KASAN: slab-use-after-free in aplic_mmio_read_offset arch/riscv/kvm/aia_aplic.c:406 Read of size 8 at addr ff600000ba965d58 by task 9498 Call Trace: aplic_read_pending arch/riscv/kvm/aia_aplic.c:119 [inline] aplic_read_pending_word arch/riscv/kvm/aia_aplic.c:351 [inline] aplic_mmio_read_offset arch/riscv/kvm/aia_aplic.c:406 kvm_riscv_aia_aplic_has_attr arch/riscv/kvm/aia_aplic.c:566 aia_has_attr arch/riscv/kvm/aia_device.c:469 allocated by task 9473: kvm_riscv_aia_aplic_init arch/riscv/kvm/aia_aplic.c:583 aia_init arch/riscv/kvm/aia_device.c:248 [inline] aia_set_attr arch/riscv/kvm/aia_device.c:334 freed by task 9473: kvm_riscv_aia_aplic_cleanup arch/riscv/kvm/aia_aplic.c:644 aia_init arch/riscv/kvm/aia_device.c:292 [inline] aia_set_attr arch/riscv/kvm/aia_device.c:334 Fix this race by acquiring dev->kvm->lock in aia_has_attr() before calling kvm_riscv_aia_aplic_has_attr(), consistent with the locking pattern used in aia_get_attr() and aia_set_attr(). Fixes: 289a007b98b06d ("RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip") Signed-off-by: Jiakai Xu Signed-off-by: Jiakai Xu Reviewed-by: Anup Patel --- V2 -> V3: - Fixed incorrect locking pattern in aia_has_attr(): avoid returning while holding dev->kvm->lock by storing the return value in a local variable, unlocking, and then returning. V1 -> V2: - Fixed the race by adding locking in aia_has_attr() instead of introducing a new validation function, as suggested by Anup Patel. --- arch/riscv/kvm/aia_device.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c index b195a93add1ce..0722cbaed5ec9 100644 --- a/arch/riscv/kvm/aia_device.c +++ b/arch/riscv/kvm/aia_device.c @@ -437,7 +437,7 @@ static int aia_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr) static int aia_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { - int nr_vcpus; + int nr_vcpus, r = -ENXIO; switch (attr->group) { case KVM_DEV_RISCV_AIA_GRP_CONFIG: @@ -466,12 +466,15 @@ static int aia_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) } break; case KVM_DEV_RISCV_AIA_GRP_APLIC: - return kvm_riscv_aia_aplic_has_attr(dev->kvm, attr->attr); + mutex_lock(&dev->kvm->lock); + r = kvm_riscv_aia_aplic_has_attr(dev->kvm, attr->attr); + mutex_unlock(&dev->kvm->lock); + return r; case KVM_DEV_RISCV_AIA_GRP_IMSIC: return kvm_riscv_aia_imsic_has_attr(dev->kvm, attr->attr); } - return -ENXIO; + return r; } struct kvm_device_ops kvm_riscv_aia_device_ops = {