CVE-2026-72138 — xen/gntdev: fix error handling in ioctl
In the Linux kernel, the following vulnerability has been resolved: xen/gntdev: fix error handling in ioctl When gntdev_ioctl_map_grant_ref() fails to copy the operation resul…
Published: 2026-08-15 · CVSS: Unscored
In the Linux kernel, the following vulnerability has been resolved: xen/gntdev: fix error handling in ioctl When gntdev_ioctl_map_grant_ref() fails to copy the operation result back to userspace after successfully adding the mapping to the list, the error path returns -EFAULT without releasing the reference acquired by gntdev_alloc_map(). The mapping remains in priv->maps with a refcount of 1, causing a memory leak and a dangling list entry. Additionally, gntdev_add_map() may modify map->index to avoid overlap with existing mappings. Therefore, the index returned to userspace must be obtained after gntdev_add_map() completes. Fix this by holding the mutex across gntdev_add_map(), retrieving the correct index, and copy_to_user(). If copy_to_user() fails, remove the mapping from the list and release the reference while still holding the lock. Fix these issues by properly handling all error cases.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7