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… (CVE-2026-46181)
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.
AI Analysis
Technical Summary
The Linux kernel vulnerability CVE-2026-46181 concerns the RDMA mlx4 driver where improper use of RCU in mlx4_srq_event() leads to potential crashes due to accessing the mlx4_srq struct outside RCU critical sections and without proper freeing. The fix involves replacing RCU with spinlocks and using refcount_inc_not_zero() to guard against partially initialized objects, ensuring the srq is fully initialized before setting reference counts. This vulnerability is part of a set of critical kernel issues addressed in Red Hat Enterprise Linux 8 kernel and kernel-rt updates. The vulnerability affects version 3.0 of the Linux kernel and has a CVSS 3.1 vector indicating local attack complexity, low privileges required, and high impact on confidentiality, integrity, and availability.
Potential Impact
Exploitation of this vulnerability can cause kernel crashes, potentially leading to denial of service. The CVSS vector indicates high impact on confidentiality, integrity, and availability, meaning successful exploitation could compromise system stability and security. However, no known exploits in the wild have been reported at this time.
Mitigation Recommendations
A patch addressing this vulnerability is available from Red Hat and other Linux distributors as part of kernel and kernel-rt updates. Systems running affected versions should apply the official security updates promptly and reboot to activate the fixes. The vendor advisory explicitly states the update must be applied and the system rebooted for remediation. No additional mitigation steps are required beyond applying the official patch.
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… (CVE-2026-46181)
Description
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.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vulnerability CVE-2026-46181 concerns the RDMA mlx4 driver where improper use of RCU in mlx4_srq_event() leads to potential crashes due to accessing the mlx4_srq struct outside RCU critical sections and without proper freeing. The fix involves replacing RCU with spinlocks and using refcount_inc_not_zero() to guard against partially initialized objects, ensuring the srq is fully initialized before setting reference counts. This vulnerability is part of a set of critical kernel issues addressed in Red Hat Enterprise Linux 8 kernel and kernel-rt updates. The vulnerability affects version 3.0 of the Linux kernel and has a CVSS 3.1 vector indicating local attack complexity, low privileges required, and high impact on confidentiality, integrity, and availability.
Potential Impact
Exploitation of this vulnerability can cause kernel crashes, potentially leading to denial of service. The CVSS vector indicates high impact on confidentiality, integrity, and availability, meaning successful exploitation could compromise system stability and security. However, no known exploits in the wild have been reported at this time.
Mitigation Recommendations
A patch addressing this vulnerability is available from Red Hat and other Linux distributors as part of kernel and kernel-rt updates. Systems running affected versions should apply the official security updates promptly and reboot to activate the fixes. The vendor advisory explicitly states the update must be applied and the system rebooted for remediation. No additional mitigation steps are required beyond applying the official patch.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_vex
- Csaf Version
- 2.0
- Publisher
- Microsoft Security Response Center
- Advisory Id
- msrc_CVE-2026-46181
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- 3.1
Threat ID: 6a19febee29bf47b500fdfa1
Added to database: 05/29/2026, 21:01:50 UTC
Last enriched: 07/03/2026, 00:56:55 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 80
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