CVE-2025-21713 powerpc/pseries/iommu: Don't unset window if it was never set
A local attacker can trigger a kernel crash by attaching a VFIO group to a container, causing a null pointer dereference in the PowerPC IOMMU driver.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-21713?
CVE-2025-21713 is a medium-severity vulnerability in Linux kernel, published on 27 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries/iommu: Don't unset window if it was never set
On pSeries, when user attempts to use the same vfio container used by different iommu group, the spapr_tce_set_window() returns -EPERM and the subsequent cleanup leads to the below crash.
Kernel attempted to read user page (308) - exploit attempt? BUG: Kernel NULL pointer dereference on read at 0x00000308 Faulting instruction address: 0xc0000000001ce358 Oops: Kernel access of bad area, sig: 11 [#1] NIP: c0000000001ce358 LR: c0000000001ce05c CTR: c00000000005add0 <snip> NIP [c0000000001ce358] spapr_tce_unset_window+0x3b8/0x510 LR [c0000000001ce05c] spapr_tce_unset_window+0xbc/0x510 Call Trace: spapr_tce_unset_window+0xbc/0x510 (unreliable) tce_iommu_attach_group+0x24c/0x340 [vfio_iommu_spapr_tce] vfio_container_attach_group+0xec/0x240 [vfio] vfio_group_fops_unl_ioctl+0x548/0xb00 [vfio] sys_ioctl+0x754/0x1580 system_call_exception+0x13c/0x330 system_call_vectored_common+0x15c/0x2ec <snip> --- interrupt: 3000
Fix this by having null check for the tbl passed to the spapr_tce_unset_window().
Weakness: CWE-476
Which versions are affected by CVE-2025-21713?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21713?
Apply the vendor's patch.
Is CVE-2025-21713 being exploited?
There is no known exploitation of CVE-2025-21713 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-21713, DEBIAN-CVE-2025-21713, GHSA-r24p-j496-7rxg, UBUNTU-CVE-2025-21713.