CVE-2026-98253
Received
Received - Intake
Race Condition in Linux Kernel RDMA/ucma Component
Vulnerability report for CVE-2026-98253, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-06
Last updated on: 2026-10-06
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 60d613b39e8d0c9f3b526e9c96445422b4562d76 |
| Linux | Linux | fe454dc31e84f8c14cb8942fcb61666c9f40745b |
| Linux | Linux | fe454dc31e84f8c14cb8942fcb61666c9f40745b |
| Linux | Linux | fe454dc31e84f8c14cb8942fcb61666c9f40745b |
| Linux | Linux | fe454dc31e84f8c14cb8942fcb61666c9f40745b |
| Linux | Linux | fe454dc31e84f8c14cb8942fcb61666c9f40745b |
| Linux | Linux | fe454dc31e84f8c14cb8942fcb61666c9f40745b |
| Linux | Linux | fe454dc31e84f8c14cb8942fcb61666c9f40745b |
| Linux | Linux | a3262b3884dd67b4c5632ce7cdf9cff9d1a575d4 |
| Linux | Linux | 5.10.20 |
| Linux | Linux | 5.11.3 |
| Linux | Linux | 5.12 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
