Description
The ZFS_IOC_USERSPACE_MANY ioctl, used by zfs-userspace(8), truncated a 64-bit output buffer size to a 32-bit integer for the kernel allocation, but used the original 64-bit size as the buffer limit when writing records. A local user with the -userused- delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.
CVSS 7.8EPSS 0.165%Risk 0.79
View source- Published
- 2026-08-19 06:17:42
- Affected versions
- unknown
- Type
- Kernel
- Last modified
- 2026-08-26 16:54:50
- Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H