Linux kernel: race condition in qbman qman_destroy_fq (dynamic FQID)
CVE-2026-23463 Published on April 3, 2026
soc: fsl: qbman: fix race condition in qman_destroy_fq
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().
Products Associated with CVE-2026-23463
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Affected Versions
Linux:- Version c535e923bb97a4b361e89a6383693482057f8b0c and below 9e3d47904b8153c8c3ad2f9b66d5008aad677aa8 is affected.
- Version c535e923bb97a4b361e89a6383693482057f8b0c and below d21923a8059fa896bfef016f55dd769299335cb4 is affected.
- Version c535e923bb97a4b361e89a6383693482057f8b0c and below 751f60bd48edaf03f9d84ab09e5ce6705757d50f is affected.
- Version c535e923bb97a4b361e89a6383693482057f8b0c and below 85dbbf7dc88b0a54f2e334daedf6f3f31fd004fa is affected.
- Version c535e923bb97a4b361e89a6383693482057f8b0c and below 265e56714635c5dd1e5964bfd97fa6e73f62cde5 is affected.
- Version c535e923bb97a4b361e89a6383693482057f8b0c and below 014077044e874e270ec480515edbc1cadb976cf2 is affected.
- Version 4.9 is affected.
- Before 4.9 is unaffected.
- Version 6.1.167, <= 6.1.* is unaffected.
- Version 6.6.130, <= 6.6.* is unaffected.
- Version 6.12.78, <= 6.12.* is unaffected.
- Version 6.18.20, <= 6.18.* is unaffected.
- Version 6.19.10, <= 6.19.* is unaffected.
- Version 7.0-rc5, <= * is unaffected.