CVE-2026-46084 RDMA/mana_ib: Disable RX steering on RSS QP destroy
A use-after-free vulnerability in the Linux kernel's RDMA/mana_ib driver allows stale steering configurations to cause kernel warnings and potential instability when RSS QPs are destroyed.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46084?
CVE-2026-46084 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mana_ib: Disable RX steering on RSS QP destroy
When an RSS QP is destroyed (e.g. DPDK exit), mana_ib_destroy_qp_rss() destroys the RX WQ objects but does not disable vPort RX steering in firmware. This leaves stale steering configuration that still points to the destroyed RX objects.
If traffic continues to arrive (e.g. peer VM is still transmitting) and the VF interface is subsequently brought up (mana_open), the firmware may deliver completions using stale CQ IDs from the old RX objects. These CQ IDs can be reused by the ethernet driver for new TX CQs, causing RX completions to land on TX CQs:
WARNING: mana_poll_tx_cq+0x1b8/0x220 [mana] (is_sq == false) WARNING: mana_gd_process_eq_events+0x209/0x290 (cq_table lookup fails)
Fix this by disabling vPort RX steering before destroying RX WQ objects. Note that mana_fence_rqs() cannot be used here because the fence completion is delivered on the CQ, which is polled by user-mode (e.g. DPDK) and not visible to the kernel driver.
Refactor the disable logic into a shared mana_disable_vport_rx() in mana_en, exported for use by mana_ib, replacing the duplicate code. The ethernet driver's mana_dealloc_queues() is also updated to call this common function.
Weakness: CWE-416
Which versions are affected by CVE-2026-46084?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46084?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-46084 being exploited?
There is no known exploitation of CVE-2026-46084 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88673, BELL-CVE-2026-46084, DEBIAN-CVE-2026-46084, GHSA-996r-prhc-hfj8, ROOT-OS-UBUNTU-2404-CVE-2026-46084, UBUNTU-CVE-2026-46084.