CVE-2026-23463

Description

In the Linux kernel, the following vulnerability has been resolved: soc: fsl: qbman: fix race condition in qman_destroy_fq When QMAN_FQ_FLAG_DYNAMIC_FQID is set, there's a race condition between fq_table[fq->idx] state and freeing/allocating from the pool and WARN_ON(fq_table[fq->idx]) in qman_create_fq() gets triggered. Indeed, we can have: Thread A Thread B qman_destroy_fq() qman_create_fq() qman_release_fqid() qman_shutdown_fq() gen_pool_free() -- At this point, the fqid is available again -- qman_alloc_fqid() -- so, we can get the just-freed fqid in thread B -- fq->fqid = fqid; fq->idx = fqid * 2; WARN_ON(fq_table[fq->idx]); fq_table[fq->idx] = fq; fq_table[fq->idx] = NULL; And adding some logs between qman_release_fqid() and fq_table[fq->idx] = NULL makes the WARN_ON() trigger a lot more. To prevent that, ensure that fq_table[fq->idx] is set to NULL before gen_pool_free() is called by using smp_wmb().

References

• https://git.kernel.org/stable/c/014077044e874e270ec480515edbc1cadb976cf2
• https://git.kernel.org/stable/c/265e56714635c5dd1e5964bfd97fa6e73f62cde5
• https://git.kernel.org/stable/c/751f60bd48edaf03f9d84ab09e5ce6705757d50f
• https://git.kernel.org/stable/c/85dbbf7dc88b0a54f2e334daedf6f3f31fd004fa
• https://git.kernel.org/stable/c/9e3d47904b8153c8c3ad2f9b66d5008aad677aa8