From:   Natalia Petrova <n.petrova@fintech.ru>
To:     Andreas Noever <andreas.noever@gmail.com>
CC:     Natalia Petrova <n.petrova@fintech.ru>,
        Michael Jamet <michael.jamet@intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Yehezkel Bernat <YehezkelShB@gmail.com>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <lvc-project@linuxtesting.org>
Subject: [PATCH] thunderbolt_tb: add check for return value of 'tb_switch_find_port'
Date:   Fri, 17 Feb 2023 16:24:32 +0300
Message-ID: <20230217132432.487106-1-n.petrova@fintech.ru>
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Return value of 'tb_switch_find_port' has to be checked to avoid
null pointer dereferences in functions tb_tunnel_alloc_dma() and
tb_port_info().

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 386e5e29d81c ("thunderbolt: Make tb_find_port() available to other files")
Signed-off-by: Natalia Petrova <n.petrova@fintech.ru>
---
 drivers/thunderbolt/tb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 9853f6c7e81d..5d6cded68d46 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -1156,6 +1156,8 @@ static int tb_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd,
 	sw = tb_to_switch(xd->dev.parent);
 	dst_port = tb_port_at(xd->route, sw);
 	nhi_port = tb_switch_find_port(tb->root_switch, TB_TYPE_NHI);
+	if (!nhi_port)
+		return -EIO;
 
 	mutex_lock(&tb->lock);
 	tunnel = tb_tunnel_alloc_dma(tb, nhi_port, dst_port, transmit_path,
-- 
2.34.1