From: Bob Pearson rpearsonhpe@gmail.com

mainline inclusion from mainline-v6.10-rc1 commit 2b23b6097303ed0ba5f4bc036a1c07b6027af5c6 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA72Y8 CVE: CVE-2024-38544

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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In rxe_comp_queue_pkt() an incoming response packet skb is enqueued to the resp_pkts queue and then a decision is made whether to run the completer task inline or schedule it. Finally the skb is dereferenced to bump a 'hw' performance counter. This is wrong because if the completer task is already running in a separate thread it may have already processed the skb and freed it which can cause a seg fault. This has been observed infrequently in testing at high scale.

This patch fixes this by changing the order of enqueuing the packet until after the counter is accessed.

Link: https://lore.kernel.org/r/20240329145513.35381-4-rpearsonhpe@gmail.com Signed-off-by: Bob Pearson rpearsonhpe@gmail.com Fixes: 0b1e5b99a48b ("IB/rxe: Add port protocol stats") Signed-off-by: Jason Gunthorpe jgg@nvidia.com

Conflicts: drivers/infiniband/sw/rxe/rxe_comp.c [Did not backport dccb23f6c312.] Signed-off-by: Liu Jian liujian56@huawei.com --- drivers/infiniband/sw/rxe/rxe_comp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_comp.c b/drivers/infiniband/sw/rxe/rxe_comp.c index aa73a54ea070..b7645de067f3 100644 --- a/drivers/infiniband/sw/rxe/rxe_comp.c +++ b/drivers/infiniband/sw/rxe/rxe_comp.c @@ -123,12 +123,12 @@ void rxe_comp_queue_pkt(struct rxe_qp *qp, struct sk_buff *skb) { int must_sched;

- skb_queue_tail(&qp->resp_pkts, skb); - - must_sched = skb_queue_len(&qp->resp_pkts) > 1; + must_sched = skb_queue_len(&qp->resp_pkts) > 0; if (must_sched != 0) rxe_counter_inc(SKB_TO_PKT(skb)->rxe, RXE_CNT_COMPLETER_SCHED);

+ skb_queue_tail(&qp->resp_pkts, skb); + rxe_run_task(&qp->comp.task, must_sched); }