[PATCH 6.1 024/132] usb: potential integer overflow in usbg_make_tpg()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chen Yufeng <chenyufeng@iie.ac.cn>

[ Upstream commit 153874010354d050f62f8ae25cbb960c17633dc5 ]

The variable tpgt in usbg_make_tpg() is defined as unsigned long and is
assigned to tpgt->tport_tpgt, which is defined as u16. This may cause an
integer overflow when tpgt is greater than USHRT_MAX (65535). I
haven't tried to trigger it myself, but it is possible to trigger it
by calling usbg_make_tpg() with a large value for tpgt.

I modified the type of tpgt to match tpgt->tport_tpgt and adjusted the
relevant code accordingly.

This patch is similar to commit 59c816c1f24d ("vhost/scsi: potential
memory corruption").

Signed-off-by: Chen Yufeng <chenyufeng@iie.ac.cn>
Link: https://lore.kernel.org/r/20250415065857.1619-1-chenyufeng@iie.ac.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/function/f_tcm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index 3c9541357c241..55a81ad6837b6 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -1321,14 +1321,14 @@ static struct se_portal_group *usbg_make_tpg(struct se_wwn *wwn,
 	struct usbg_tport *tport = container_of(wwn, struct usbg_tport,
 			tport_wwn);
 	struct usbg_tpg *tpg;
-	unsigned long tpgt;
+	u16 tpgt;
 	int ret;
 	struct f_tcm_opts *opts;
 	unsigned i;
 
 	if (strstr(name, "tpgt_") != name)
 		return ERR_PTR(-EINVAL);
-	if (kstrtoul(name + 5, 0, &tpgt) || tpgt > UINT_MAX)
+	if (kstrtou16(name + 5, 0, &tpgt))
 		return ERR_PTR(-EINVAL);
 	ret = -ENODEV;
 	mutex_lock(&tpg_instances_lock);
-- 
2.39.5