CVE Catalog

CVE-2026-74698

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the mlx5e network driver has a vulnerability due to incorrect BQL reset on SQ re-activation. mlx5e_activate_txqsq() unconditionally calls netdev_tx_reset_queue(), zeroing BQL counters of channels with in-flight TX WQEs, leading to BUG_ON in dql_completed().

Risk Assessment

An attacker could cause a kernel crash (kernel BUG) by triggering SQ re-activation, potentially resulting in network interface or system disruption.

Recommendation

Apply a Linux kernel update containing the fix that resets BQL only when the SQ has no bytes in flight (sq->cc == sq->pc).

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: fix BQL reset on SQ re-activation mlx5e_queue_start() deactivates and re-activates all channels but closes only the queue being restarted. mlx5e_activate_txqsq() then unconditionally calls netdev_tx_reset_queue(), zeroing the BQL counters of channels that kept their in-flight TX WQEs. The next completion then over-charges and trips the BUG_ON() in dql_completed(): kernel BUG at lib/dynamic_queue_limits.c:99! RIP: 0010:dql_completed+0x23d/0x280 Call Trace: <IRQ> mlx5e_poll_tx_cq+0x668/0xa60 mlx5e_napi_poll+0x5b/0x7b0 net_rx_action+0x15a/0x580 Reset BQL only when the SQ has no bytes in flight (sq->cc == sq->pc). In the case that reset is skipped, the outstanding WQEs will eventually complete and rebalance the dql. The dql->limit is carried across the reset.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS