CVE-2026-46181: Linux kernel · RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in f0dbd9355ce1e93808541260c7ffab7956df9233 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in f0dbd9355ce1e93808541260c7ffab7956df9233, c9341307ea16b9395c2e4c9c94d8499d91fe31d0, 8b7833f3bce35cb0d01c1503781523c099c675f0 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
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.
References
- git.kernel.org/stable/c/2d8b30b496bc53e961ba7415fd629fc27813017c (opens in a new tab)
- git.kernel.org/stable/c/f0dbd9355ce1e93808541260c7ffab7956df9233 (opens in a new tab)
- git.kernel.org/stable/c/1e2a44875b6afb4add1115f7f3351dcbeb6f273d (opens in a new tab)
- git.kernel.org/stable/c/8b7833f3bce35cb0d01c1503781523c099c675f0 (opens in a new tab)
- git.kernel.org/stable/c/c9341307ea16b9395c2e4c9c94d8499d91fe31d0 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-46181 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2482532 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46181.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36216 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41236 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34095 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34443 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34094 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:25217 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:25121 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35896 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35894 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35863 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:25120 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33900 (opens in a new tab)