CVE-2026-74397 IB/mlx5: Fix transport-domain rollback and initialize lb mutex earlier
A memory leak in the Linux kernel mlx5 InfiniBand driver occurs when loopback enablement fails, potentially leading to resource exhaustion and denial of service.
- 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-2026-74397?
CVE-2026-74397 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 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:
IB/mlx5: Fix transport-domain rollback and initialize lb mutex earlier
mlx5_ib_alloc_transport_domain() allocates a transport domain and then may fail in mlx5_ib_enable_lb(). In that case, the allocated TD is leaked.
Fix this by deallocating the TD when mlx5_ib_enable_lb() returns an error. Also return 0 explicitly in the no-loopback-capability success branch, and move dev->lb.mutex initialization to mlx5_ib_stage_init_init().
Which versions are affected by CVE-2026-74397?
How do I fix CVE-2026-74397?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74397 being exploited?
There is no known exploitation of CVE-2026-74397 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74397, DEBIAN-CVE-2026-74397, GHSA-85rj-hfqq-77v3, UBUNTU-CVE-2026-74397.