From: Qihang Tang <q.h.hack.winter@gmail.com> stable inclusion from stable-v5.10.261 commit 0f310bac6db9bd3bb1655707d692d9d2a86eeb17 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18146 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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 <eperezma@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Qihang Tang <q.h.hack.winter@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260508075821.92656-1-q.h.hack.winter@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Fanhua Li <lifanhua5@huawei.com> --- 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 88c9d7665cedb..56d99c3d0a389 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -1567,16 +1567,32 @@ 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; vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); if (remap_pfn_range(vma, vmf->address & PAGE_MASK, @@ -1605,8 +1621,6 @@ 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; @@ -1614,7 +1628,8 @@ 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) -- 2.43.0