Linux Kernel RCU Misuse in mlx4 SRQ Event Handling
CVE-2026-46181 Published on May 28, 2026

RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event()
In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event() Sashiko points out the radix_tree itself is RCU safe, but nothing ever frees the mlx4_srq struct with RCU, and it isn't even accessed within the RCU critical section. It also will crash if an event is delivered before the srq object is finished initializing. Use the spinlock since it isn't easy to make RCU work, use refcount_inc_not_zero() to protect against partially initialized objects, and order the refcount_set() to be after the srq is fully initialized.

NVD

Vulnerability Analysis

CVE-2026-46181 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
LOCAL
Attack Complexity:
HIGH
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Race Condition within a Thread

If two threads of execution use a resource simultaneously, there exists the possibility that resources may be used while invalid, in turn making the state of execution undefined.


Products Associated with CVE-2026-46181

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Linux Kernel
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Rhel E4s
 
Red Hat Rhel Eus
 

Affected Versions

Linux: Linux: Red Hat Enterprise Linux AppStream E4S (v.9.2): Red Hat Enterprise Linux AppStream E4S (v.9.4): Red Hat Enterprise Linux AppStream EUS (v.9.6): Red Hat Enterprise Linux AppStream (v. 9): Red Hat Enterprise Linux BaseOS (v. 8): Red Hat Enterprise Linux BaseOS E4S (v.9.2): Red Hat Enterprise Linux BaseOS E4S (v.9.4): Red Hat Enterprise Linux BaseOS EUS (v.9.6): Red Hat Enterprise Linux BaseOS (v. 9): Red Hat Enterprise Linux CRB (v. 8): Red Hat CodeReady Linux Builder EUS (v.9.6): Red Hat Enterprise Linux CodeReady Linux Builder (v. 9): Red Hat Enterprise Linux NFV (v. 8): Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2): Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4): Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6): Red Hat Enterprise Linux Real Time for NFV (v. 9): Red Hat Enterprise Linux RT (v. 8): Red Hat Enterprise Linux Real Time E4S (v.9.2): Red Hat Enterprise Linux Real Time E4S (v.9.4): Red Hat Enterprise Linux Real Time EUS (v.9.6): Red Hat Enterprise Linux Real Time (v. 9): Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 6:

Exploit Probability

EPSS
0.14%
Percentile
3.37%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.