5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bjoern Doebel <redacted>
[ Upstream commit 22b8fbded65b8c441b634a185f8da67657df6c50 ]
get_srq_wqe() reads wqe->dma.num_sge from the shared receive queue
buffer, which is mapped into userspace. It validates num_sge against
max_sge, but then re-reads the same field to calculate the memcpy
size. A concurrent userspace thread can modify num_sge between
validation and use, causing a heap buffer overflow when copying the
WQE into qp->resp.srq_wqe.
Read num_sge into a local variable and use it for both the bounds
check and the size calculation.
Fixes: 8700e3e7c485 ("Soft RoCE driver")
Link: https://patch.msgid.link/r/20260518215040.1598586-2-tristan@talencesecurity.com (local)
Signed-off-by: Tristan Madani <redacted>
Reviewed-by: Zhu Yanjun <redacted>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
[doebel: cherry-picked from v6.1.178 (3cfa2a3adc51), adjusted for
context]
Signed-off-by: Bjoern Doebel <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/sw/rxe/rxe_resp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index e7dec84810614..27f24c77993ca 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -296,6 +296,7 @@ static enum resp_states get_srq_wqe(struct rxe_qp *qp)
struct rxe_recv_wqe *wqe;
struct ib_event ev;
unsigned int count;
+ unsigned int num_sge;
size_t size;
if (srq->error)
@@ -310,12 +311,13 @@ static enum resp_states get_srq_wqe(struct rxe_qp *qp)
}
/* don't trust user space data */
- if (unlikely(wqe->dma.num_sge > srq->rq.max_sge)) {
+ num_sge = wqe->dma.num_sge;
+ if (unlikely(num_sge > srq->rq.max_sge)) {
spin_unlock_bh(&srq->rq.consumer_lock);
pr_warn("%s: invalid num_sge in SRQ entry\n", __func__);
return RESPST_ERR_MALFORMED_WQE;
}
- size = sizeof(*wqe) + wqe->dma.num_sge*sizeof(struct rxe_sge);
+ size = sizeof(*wqe) + num_sge * sizeof(struct rxe_sge);
memcpy(&qp->resp.srq_wqe, wqe, size);
qp->resp.wqe = &qp->resp.srq_wqe.wqe;--
2.53.0