Status: UPDATED | Advisory ID: CVE-2026-98253
| CVE | CVE-2026-98253 |
| CVSS Score / Version | 7.8 (High) / CVSS v3.1 |
| Updated | 2026-10-07 |
| CVSS Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CVSS Prose | attack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | Linux Kernel |
| Vendor | Product | Affected Versions | Patch Status |
|---|---|---|---|
| Linux | Linux Kernel |
| Subsystems | OT Supporting Infrastructure |
| Sectors | All Sectors |
In the Linux kernel, the following vulnerability has been resolved:
RDMA/ucma: Serialize join and leave on copy_to_user failure
rdma_join_multicast() queues RoCE work that later reads the ucma_multicast
through event->param.ud.private_data, then list_add()s the CMA multicast
at the head of id_priv->mc_list. rdma_leave_multicast() matches only by
sockaddr and destroys the first hit.
ucma_process_join() used to drop ctx->mutex after a successful join and
retake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls
with the same address can therefore insert a second CMA entry before the
first thread's leave. leave then cancels the newer work and the older
worker still dereferences the ucma_multicast that the first thread frees.
Keep ctx->mutex held from rdma_join_multicast() through copy_to_user() and,
on -EFAULT, through rdma_leave_multicast() so leave cannot miss this join.
Do not leave if join itself failed: that path never published this address
on mc_list, and a leave-by-addr would destroy an earlier successful join. (NVD)
Monitor Linux's web page for any future patch releases.
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-98253 |
| CVE | https://www.cve.org/CVERecord?id=CVE-2026-98253 |