From 283861a4c52c1ea4df3dd1b6fc75a50796ce3524 Mon Sep 17 00:00:00 2001
From: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Date: Thu, 2 Feb 2023 10:48:50 -0800
Subject: [PATCH 1/1] RDMA/cxgb4: Fix potential null-ptr-deref in
pass_establish()
Git-commit: 283861a4c52c1ea4df3dd1b6fc75a50796ce3524
Patch-mainline: v6.3-rc1
References: git-fixes
If get_ep_from_tid() fails to lookup non-NULL value for ep, ep is
dereferenced later regardless of whether it is empty.
This patch adds a simple sanity check to fix the issue.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 944661dd97f4 ("RDMA/iw_cxgb4: atomically lookup ep and get a reference")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Link: https://lore.kernel.org/r/20230202184850.29882-1-n.zhandarovich@fintech.ru
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Nicolas Morey <nmorey@suse.com>
---
drivers/infiniband/hw/cxgb4/cm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index ea3ddf0d2411..ced615b5ea09 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -2676,6 +2676,9 @@ static int pass_establish(struct c4iw_dev *dev, struct sk_buff *skb)
u16 tcp_opt = ntohs(req->tcp_opt);
ep = get_ep_from_tid(dev, tid);
+ if (!ep)
+ return 0;
+
pr_debug("ep %p tid %u\n", ep, ep->hwtid);
ep->snd_seq = be32_to_cpu(req->snd_isn);
ep->rcv_seq = be32_to_cpu(req->rcv_isn);
--
2.39.1.1.gbe015eda0162