CVE-2023-53811
Description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/irdma: Cap MSIX used to online CPUs + 1
The irdma driver can use a maximum number of msix vectors equal to num_online_cpus() + 1 and the kernel warning stack below is shown if that number is exceeded.
The kernel throws a warning as the driver tries to update the affinity hint with a CPU mask greater than the max CPU IDs. Fix this by capping the MSIX vectors to num_online_cpus() + 1.
WARNING: CPU: 7 PID: 23655 at include/linux/cpumask.h:106 irdma_cfg_ceq_vector+0x34c/0x3f0 [irdma] RIP: 0010:irdma_cfg_ceq_vector+0x34c/0x3f0 [irdma] Call Trace: irdma_rt_init_hw+0xa62/0x1290 [irdma] ? irdma_alloc_local_mac_entry+0x1a0/0x1a0 [irdma] ? __is_kernel_percpu_address+0x63/0x310 ? rcu_read_lock_held_common+0xe/0xb0 ? irdma_lan_unregister_qset+0x280/0x280 [irdma] ? irdma_request_reset+0x80/0x80 [irdma] ? ice_get_qos_params+0x84/0x390 [ice] irdma_probe+0xa40/0xfc0 [irdma] ? rcu_read_lock_bh_held+0xd0/0xd0 ? irdma_remove+0x140/0x140 [irdma] ? rcu_read_lock_sched_held+0x62/0xe0 ? down_write+0x187/0x3d0 ? auxiliary_match_id+0xf0/0x1a0 ? irdma_remove+0x140/0x140 [irdma] auxiliary_bus_probe+0xa6/0x100 __driver_probe_device+0x4a4/0xd50 ? __device_attach_driver+0x2c0/0x2c0 driver_probe_device+0x4a/0x110 __driver_attach+0x1aa/0x350 bus_for_each_dev+0x11d/0x1b0 ? subsys_dev_iter_init+0xe0/0xe0 bus_add_driver+0x3b1/0x610 driver_register+0x18e/0x410 ? 0xffffffffc0b88000 irdma_init_module+0x50/0xaa [irdma] do_one_initcall+0x103/0x5f0 ? perf_trace_initcall_level+0x420/0x420 ? do_init_module+0x4e/0x700 ? __kasan_kmalloc+0x7d/0xa0 ? kmem_cache_alloc_trace+0x188/0x2b0 ? kasan_unpoison+0x21/0x50 do_init_module+0x1d1/0x700 load_module+0x3867/0x5260 ? layout_and_allocate+0x3990/0x3990 ? rcu_read_lock_held_common+0xe/0xb0 ? rcu_read_lock_sched_held+0x62/0xe0 ? rcu_read_lock_bh_held+0xd0/0xd0 ? __vmalloc_node_range+0x46b/0x890 ? lock_release+0x5c8/0xba0 ? alloc_vm_area+0x120/0x120 ? selinux_kernel_module_from_file+0x2a5/0x300 ? __inode_security_revalidate+0xf0/0xf0 ? __do_sys_init_module+0x1db/0x260 __do_sys_init_module+0x1db/0x260 ? load_module+0x5260/0x5260 ? do_syscall_64+0x22/0x450 do_syscall_64+0xa5/0x450 entry_SYSCALL_64_after_hwframe+0x66/0xdb
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
In the Linux kernel's irdma driver, excessive MSI-X vector allocation causes a kernel warning when the CPU affinity hint exceeds online CPUs; the fix caps vectors to num_online_cpus()+1.
Root
Cause
The irdma InfiniBand/RDMA driver attempted to allocate more MSI-X vectors than available CPU cores, triggering a kernel warning. The driver used the requested number of vectors to update the CPU affinity hint for completion event queue (CEQ) vectors, but the cpumask operation overflowed when the vector index exceeded the highest possible CPU ID. This results in a WARN_ON at cpumask.h:106 during irdma_cfg_ceq_vector() [1][2].
Exploitation
No special attacker access is needed; the issue arises automatically on systems where the irdma device reports more MSI-X vectors than the number of online CPUs plus one. The warning is triggered during driver probe (irdma_probe() -> irdma_rt_init_hw()) when the hardware configuration requests a vector count exceeding the safe limit [1][2].
Impact
The immediate impact is a kernel warning and possible stack trace printed to the console, which can degrade system stability and cause log noise. The improper CPU affinity mask may also lead to suboptimal interrupt routing, though the official source does not claim a denial of service or privilege escalation [2].
Mitigation
The fix caps the number of MSI-X vectors used by the irdma driver to num_online_cpus() + 1, ensuring the affinity hint never exceeds the valid CPU set. The patch has been applied to the stable kernel trees as of December 2025 [1][2]. Users should update to a kernel version containing this commit to eliminate the warning and ensure correct interrupt handling.
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
2Patches
487674a359ad1b3bd44bf20cb209e4aa9a7b69cd9842c4699Vulnerability mechanics
Generated on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
4News mentions
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