From: Michael Ferolito <michaelsunn101@gmail.com>
Date: Tue, 28 Jan 2025 03:09:45 +0000 (-0600)
Subject: usb: gadget: g_dnl: Fix NULLPTR dereference when serial# is unset
X-Git-Tag: v2025.04-rc3~19^2~11
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dcf1c627cf436191919c5a3b153d1033245b54b7;p=thirdparty%2Fu-boot.git

usb: gadget: g_dnl: Fix NULLPTR dereference when serial# is unset

The current behaviour of this function will dereference a null pointer
if the serial# environment variable is unset. This was discovered on a
board where U-Boot did not have access to the first 256MB of ram,
resulting in a board crash.
In the event that U-Boot has full access to memory, it will still read
from address 0, which is probably not optimal.
This simple check is enough to fix it

Signed-off-by: Michael Ferolito <michaelsunn101@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20250128030945.1219589-1-michaelsunn101@gmail.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---

diff --git a/drivers/usb/gadget/g_dnl.c b/drivers/usb/gadget/g_dnl.c
index 631969b3405..f2540eb6ded 100644
--- a/drivers/usb/gadget/g_dnl.c
+++ b/drivers/usb/gadget/g_dnl.c
@@ -207,7 +207,8 @@ void g_dnl_clear_detach(void)
 static int on_serialno(const char *name, const char *value, enum env_op op,
 		int flags)
 {
-	g_dnl_set_serialnumber((char *)value);
+	if (value)
+		g_dnl_set_serialnumber((char *)value);
 	return 0;
 }
 U_BOOT_ENV_CALLBACK(serialno, on_serialno);