Coverity reports a data race where pmd_alloc_static_tx_qid() accesses
pmd->static_tx_qid in the VLOG_DBG() call without holding the
tx_qid_pool_mutex, while id_pool_alloc_id() writes to static_tx_qid
with the mutex held.
The race occurs because the VLOG_DBG() call is placed after the mutex
unlock. While this is a debug-only log with minimal practical impact,
it violates proper locking discipline and could theoretically read a
stale or inconsistent value.
Fix by moving the VLOG_DBG() call before the mutex unlock, ensuring
the read of static_tx_qid is protected by the same lock that protects
the write.
Fixes: 140dd699463a ("dpif-netdev: Incremental addition/deletion of PMD
threads.")
Signed-off-by: Eelco Chaudron <[email protected]>
---
lib/dpif-netdev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 9df05c4c2..54f3c8c56 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -6466,10 +6466,10 @@ pmd_alloc_static_tx_qid(struct dp_netdev_pmd_thread
*pmd)
VLOG_ABORT("static_tx_qid allocation failed for PMD on core %2d"
", numa_id %d.", pmd->core_id, pmd->numa_id);
}
- ovs_mutex_unlock(&pmd->dp->tx_qid_pool_mutex);
VLOG_DBG("static_tx_qid = %d allocated for PMD thread on core %2d"
", numa_id %d.", pmd->static_tx_qid, pmd->core_id, pmd->numa_id);
+ ovs_mutex_unlock(&pmd->dp->tx_qid_pool_mutex);
}
static void
--
2.52.0
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
