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 C3C5D397E80; Tue, 21 Jul 2026 20:34:10 +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=1784666051; cv=none; b=l5sfxzjADKkhM+PIEZDBbUizf1tKlTZTR0T3pBryZXDhA/W+EP7/+/h2hJyx2YssKewuGg4YWWJphY16gD/oByv0pMVlfu02pQQsdbMbr7/wMRNkFRBP0Y5zgC1oKwJ15HXDhC9ng5tewbD9EIRCKE9s8HHxR+d1H42L/l6s3eY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784666051; c=relaxed/simple; bh=bSdjckCwPt7sYpf+/MpZMbRiWL6G8NZi8ui95mOYTSw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=M8jBCFXFDVLAebxVGw/uKQynMD9R55p02WqSPWoJoiPy1NWXdJ+qc93aVPSgcENZNP3TruEm7CksByexEzzo6ZaJW7997fwGiz6QkxhHRKzrO/lrogETcsYx8UkZYl5t82bsfeRk+ML9D+RwS1tQ7SOXmjR5/kY7rRpIivA/mRA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=judn1YQt; 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="judn1YQt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3649A1F000E9; Tue, 21 Jul 2026 20:34:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784666050; bh=EDMxnJv9CQlTzVCjpyAi3Pf0VlKH72QD0AtpzL13/Q8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=judn1YQtG6QFqjYZCa6rd/eEvuusMZQkCoLVOpGwdMjufqfkITIaeh+/dnYKrzOz8 8wbR+cnXPYfF1EnH/CebMCXoPnIvNBtbN07EQPF32DxDxcJAZIAE39c2e6rS1BBbtH 3tnKrIplnm/XF8kvdWTZ2d7BHds55M+0T1vWhncM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Eugenio=20P=C3=A9rez?= , "Michael S. Tsirkin" , Qihang Tang , Sasha Levin Subject: [PATCH 6.6 0535/1266] vhost/vdpa: validate virtqueue index in mmap and fault paths Date: Tue, 21 Jul 2026 17:16:12 +0200 Message-ID: <20260721152453.834020207@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qihang Tang [ Upstream commit 929e4f044621c8cc30b612fb74e1410bef09e41b ] vhost_vdpa_mmap() and vhost_vdpa_fault() use vma->vm_pgoff as a virtqueue index for get_vq_notification(), but they do not validate that the index is smaller than v->nvqs. The ioctl path already performs both a bounds check and array_index_nospec(), but the mmap/fault path only checks that the index fits in u16. This allows an out-of-range queue index to reach driver-specific get_vq_notification() callbacks. Fix this by extracting a unified vhost_vdpa_get_vq_notification() helper that validates the queue index against v->nvqs and applies array_index_nospec() before calling the driver callback. Both the mmap and fault paths use this helper, and the bounds checking is consolidated into a single location. >>From source inspection, the most defensible impact is out-of-bounds access in the callback path, potentially leading to invalid PFN remaps and crash/DoS. Fixes: ddd89d0a059d ("vhost_vdpa: support doorbell mapping via mmap") Acked-by: Eugenio Pérez Acked-by: Michael S. Tsirkin Signed-off-by: Qihang Tang Signed-off-by: Michael S. Tsirkin Message-ID: <20260508075821.92656-1-q.h.hack.winter@gmail.com> Signed-off-by: Sasha Levin --- drivers/vhost/vdpa.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index f4da76fa235eae..3645d83f240d9d 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -1377,16 +1377,32 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep) } #ifdef CONFIG_MMU -static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf) +static int +vhost_vdpa_get_vq_notification(struct vhost_vdpa *v, unsigned long index, + struct vdpa_notification_area *notify) { - struct vhost_vdpa *v = vmf->vma->vm_file->private_data; struct vdpa_device *vdpa = v->vdpa; const struct vdpa_config_ops *ops = vdpa->config; + + if (index > 65535 || index >= v->nvqs) + return -EINVAL; + + index = array_index_nospec(index, v->nvqs); + + *notify = ops->get_vq_notification(vdpa, index); + + return 0; +} + +static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf) +{ + struct vhost_vdpa *v = vmf->vma->vm_file->private_data; struct vdpa_notification_area notify; struct vm_area_struct *vma = vmf->vma; - u16 index = vma->vm_pgoff; + unsigned long index = vma->vm_pgoff; - notify = ops->get_vq_notification(vdpa, index); + if (vhost_vdpa_get_vq_notification(v, index, ¬ify)) + return VM_FAULT_SIGBUS; return vmf_insert_pfn(vma, vmf->address & PAGE_MASK, PFN_DOWN(notify.addr)); } @@ -1409,8 +1425,6 @@ static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma) return -EINVAL; if (vma->vm_flags & VM_READ) return -EINVAL; - if (index > 65535) - return -EINVAL; if (!ops->get_vq_notification) return -ENOTSUPP; @@ -1418,7 +1432,8 @@ static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma) * support the doorbell which sits on the page boundary and * does not share the page with other registers. */ - notify = ops->get_vq_notification(vdpa, index); + if (vhost_vdpa_get_vq_notification(v, index, ¬ify)) + return -EINVAL; if (notify.addr & (PAGE_SIZE - 1)) return -EINVAL; if (vma->vm_end - vma->vm_start != notify.size) -- 2.53.0