[PATCH 5.10 130/236] Bluetooth: increase BTNAMSIZ to 21 chars to fix potential buffer overflow

From: Greg Kroah-Hartman
Date: Mon Sep 13 2021 - 09:45:05 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

[ Upstream commit 713baf3dae8f45dc8ada4ed2f5fdcbf94a5c274d ]

An earlier commit replaced using batostr to using %pMR sprintf for the
construction of session->name. Static analysis detected that this new
method can use a total of 21 characters (including the trailing '\0')
so we need to increase the BTNAMSIZ from 18 to 21 to fix potential
buffer overflows.

Addresses-Coverity: ("Out-of-bounds write")
Fixes: fcb73338ed53 ("Bluetooth: Use %pMR in sprintf/seq_printf instead of batostr")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/bluetooth/cmtp/cmtp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/cmtp/cmtp.h b/net/bluetooth/cmtp/cmtp.h
index c32638dddbf9..f6b9dc4e408f 100644
--- a/net/bluetooth/cmtp/cmtp.h
+++ b/net/bluetooth/cmtp/cmtp.h
@@ -26,7 +26,7 @@
#include <linux/types.h>
#include <net/bluetooth/bluetooth.h>

-#define BTNAMSIZ 18
+#define BTNAMSIZ 21

/* CMTP ioctl defines */
#define CMTPCONNADD _IOW('C', 200, int)
--
2.30.2