# Re: \[PATCH\] net: sched: avoid qdisc\_reset\_all\_tx\_gt() vs dequeue race for lockless qdiscs

- From: patchwork-bot+netdevbpf@kernel.org
- Date: 2026-03-05 02:00:10 
- List: netdev
- Page: https://ratatoskr.run/netdev/2026/03/3441206
- Thread: https://ratatoskr.run/netdev/2026/02/3432560/t.md

```text
Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski [ref]:

On Sat, 28 Feb 2026 23:53:07 +0900 you wrote:
> When shrinking the number of real tx queues,
> netif_set_real_num_tx_queues() calls qdisc_reset_all_tx_gt() to flush
> qdiscs for queues which will no longer be used.
> 
> qdisc_reset_all_tx_gt() currently serializes qdisc_reset() with
> qdisc_lock(). However, for lockless qdiscs, the dequeue path is
> serialized by qdisc_run_begin/end() using qdisc->seqlock instead, so
> qdisc_reset() can run concurrently with __qdisc_run() and free skbs
> while they are still being dequeued, leading to UAF.
> 
> [...]

Here is the summary with links:
  - net: sched: avoid qdisc_reset_all_tx_gt() vs dequeue race for lockless qdiscs
    https://git.kernel.org/netdev/net/c/7f083faf59d1

You are awesome, thank you!
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```