net: team: stop reusing skb after queue override

A nonzero dev_queue_xmit() result does not return ownership of the skb.
When an override port's qdisc drops it, the queue override helper used to
try another port or the mode transmit op with the freed skb.

Return the handoff decision separately from transmit success. Select only
the first override port under RCU and stop after handing it the skb,
regardless of the lower transmit result. Keep the existing success and
drop accounting.

  BUG: KASAN: slab-use-after-free in sk_skb_reason_drop
  Write of size 4 by task poc/5040
  sk_skb_reason_drop (net/core/skbuff.c:1240)
  dev_kfree_skb_any_reason (net/core/dev.c:3470)
  ab_transmit (drivers/net/team/team_mode_activebackup.c:49)
  team_xmit (drivers/net/team/team_core.c:1849)
  __dev_direct_xmit (net/core/dev.c:4934)
  Freed by task 5040:
  __tcf_kfree_skb_list (net/sched/sch_generic.c:43)
  __dev_queue_xmit (net/core/dev.c:4831)
  team_xmit (drivers/net/team/team_core.c:1846)
  Kernel panic - not syncing: KASAN: panic_on_warn set ...

Cc: stable@vger.kernel.org
Fixes: 8ff5105a2b ("team: add support for queue override by setting queue_id for port")
Reported-by: <co+2cf741c3005abc20@bugs.sh>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Link: https://patch.msgid.link/20261001182326.572045-2-bestswngs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Weiming Shi 2026-10-02 02:23:25 +08:00 • committed by Jakub Kicinski
commit b7454f1940