Executive brief
A vulnerability in the Linux kernel's RDMA (Remote Direct Memory Access) component could allow a local attacker to cause a system deadlock. This issue occurs during specific memory management operations, potentially leading to a complete service outage or system instability. The flaw specifically affects systems using iWARP Connection Manager (iwcm) for high-performance networking.
Technical details
A deadlock vulnerability exists in the RDMA/iwcm component of the Linux kernel. The issue stems from the 'iwcm_wq' workqueue being created without the WQ_MEM_RECLAIM flag, while the 'flush_workqueue' function is subsequently called during paths that may involve memory reclamation. This violates forward-progress guarantees in the kernel's workqueue subsystem, specifically triggering a 'check_flush_dependency' warning and potential hang. An attacker with local access could potentially trigger this condition to cause a Denial of Service (DoS). The fix involves adding the WQ_MEM_RECLAIM flag to the workqueue allocation in 'drivers/infiniband/core/iwcm.c'.
Affected products
- Linux Linux Kernel from 4.19.320 before 5.4
Timeline
- 2024-08-20: patched: Initial patch authored by Zhu Yanjun
- 2024-10-21: advisory: CVE-2024-47696 published in NVD
References
- https://git.kernel.org/stable/c/29b3bbd912b8db86df7a3c180b910ccb621f5635
- https://git.kernel.org/stable/c/2efe8da2ddbf873385b4bc55366d09350b408df6
- https://git.kernel.org/stable/c/86dfdd8288907f03c18b7fb462e0e232c4f98d89
- https://git.kernel.org/stable/c/8b7df76356d098f85f3bd2c7cf6fb43f531893d7
- https://git.kernel.org/stable/c/a09dc967b3c58899e259c0aea092f421d22a0b04
- https://git.kernel.org/stable/c/a64f30db12bdc937c5108158d98c8eab1925c548
- https://git.kernel.org/stable/c/c8b18a75282cfd27822a8cc3c1f005c1ac8d1a58