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From:   Sjoerd Simons <sjoerd.simons@collabora.co.uk>
To:     linux-um@lists.infradead.org
Cc:     Anton Ivanov <anton.ivanov@cambridgegreys.com>,
        Jeff Dike <jdike@addtoit.com>,
        Richard Weinberger <richard@nod.at>,
        linux-kernel@vger.kernel.org
Subject: [PATCH] um: vector: Avoid NULL ptr deference if transport is unset
Date:   Sun, 16 Feb 2020 22:36:24 +0100
Message-Id: <20200216213624.800463-1-sjoerd.simons@collabora.co.uk>
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Sender: linux-kernel-owner@vger.kernel.org
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When the transport option of a vec isn't set strncmp ends up being
called on a NULL pointer. Better not do that.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>

---

 arch/um/drivers/vector_kern.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c
index 0ff86391f77d..ca90666c0b61 100644
--- a/arch/um/drivers/vector_kern.c
+++ b/arch/um/drivers/vector_kern.c
@@ -198,6 +198,9 @@ static int get_transport_options(struct arglist *def)
 	long parsed;
 	int result = 0;
 
+	if (transport == NULL)
+		return -EINVAL;
+
 	if (vector != NULL) {
 		if (kstrtoul(vector, 10, &parsed) == 0) {
 			if (parsed == 0) {
-- 
2.25.0