CVE-2026-98972
UnknownSummary
In the Linux kernel cgroup/cpuset subsystem, is_in_v2_mode() may be called in a context where a new cgroup filesystem is being rebound with a stale cpuset_cgrp_subsys.root pointer. To avoid a potential use-after-free, a new cpuset_v2_mode flag is set when the cpuset_v2_mode mount option is used and written only when cpuset_bind() runs with a stable cpuset_cgrp_subsys.root value. is_in_v2_mode() now reads this flag instead of accessing cpuset_cgrp_subsys.root directly.
Risk Assessment
A potential use-after-free in the kernel can lead to system crashes or, under favorable conditions, privilege escalation. The risk applies to systems using cgroups v2 with the cpuset controller.
Recommendation
Update the Linux kernel to a version with the fix introducing the cpuset_v2_mode flag. Until patched, avoid frequent remounting of the cgroup filesystem with the cpuset_v2_mode option.
Other vulnerabilities in Linux kernel
See all- CVE-2026-58942High
In do_fault_around of memory.c, there is a possible use after free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58847Unknown
In kvm_vfio_pviommu_attach of vfio.c, there is a possible double free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
- CVE-2026-58829High
In fuse_backing_mmap of backing.c, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58828High
In multiple functions of base.c, there is a possible use-after-free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58827High
In multiple functions of dma-buf.c, there is a possible use after free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58826High
In ksys_unshare of fork.c, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58825High
In multiple functions of fork.c, there is a possible use after free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-99242Unknown
In the Linux kernel, a race between fallocate and mmap reads in NTFS was fixed. Fallocate only took invalidate_lock for punch hole, collapse range and insert range operations, and during standard allocation new clusters were mapped before being zeroed, allowing concurrent mmap page faults to read uninitialized disk data.
- CVE-2026-99241Unknown
In the Linux kernel, a missing lock in ntfs_filemap_page_mkwrite() was fixed; it called iomap_page_mkwrite() without holding mapping->invalidate_lock. A concurrent truncate or fallocate could be invalidating pagecache and rewriting the runlist while the write fault mapped blocks and dirtied the folio.
- CVE-2026-99240Unknown
In the Linux kernel, the DAMON subsystem (mm/damon/core) has a division-by-zero bug when a DAMOS quota goal has a target_value of zero. The fix moves handling of this corner case to the core layer by adding validation in damos_commit_quota_goal(), which now returns an error for zero target values.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode() After seeing the patch [1] to guard is_in_v2_mode() with RCU, it makes me realize that is_in_v2_mode() may be called in a context where a new cgroup filesystem is being rebound with stale cpuset_cgrp_subsys.root pointer. Avoid this potential UaF situation by adding a new cpuset_v2_mode flag which is set when the cpuset_v2_mode mount option is used. This flag is written into only when cpuset_bind() is being called with a stable cpuset_cgrp_subsys.root value. The is_in_v2_mode() helper is modified to read the new cpuset_v2_mode flag instead of accessing cpuset_cgrp_subsys.root directly. [1] https://lore.kernel.org/lkml/[email protected]
Vulnerability data from NVD (NIST) · CISA KEV · EPSS