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From: Yiyuan Guo <yguoaz@gmail.com>
To: gregkh@linuxfoundation.org, dan.scally@ideasonboard.com,
	andriy.shevchenko@linux.intel.com
Cc: frank.li@nxp.com, christophe.jaillet@wanadoo.fr,
	jgilab@gmail.com, chanh@os.amperecomputing.com,
	linux-usb@vger.kernel.org, yguoaz@gmail.com
Subject: [PATCH] usb: gadget: configfs: Prevent buffer overrun in usb_string_copy
Date: Fri, 30 Jun 2023 19:04:01 +0800	[thread overview]
Message-ID: <20230630110401.2360746-1-yguoaz@gmail.com> (raw)

In usb_string_copy(), when `strlen(s) == 0`, `str[ret - 1]` accesses at
index -1. Add a check to prevent buffer overrun when `s` is empty.

Signed-off-by: Yiyuan Guo <yguoaz@gmail.com>
---
 drivers/usb/gadget/configfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 4c639e9ddedc..457dbc267964 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -127,7 +127,7 @@ static int usb_string_copy(const char *s, char **s_copy)
 			return -ENOMEM;
 	}
 	strcpy(str, s);
-	if (str[ret - 1] == '\n')
+	if (ret && str[ret - 1] == '\n')
 		str[ret - 1] = '\0';
 	*s_copy = str;
 	return 0;
-- 
2.25.1


             reply	other threads:[~2023-06-30 11:05 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-30 11:04 Yiyuan Guo [this message]
2023-06-30 12:17 ` [PATCH] usb: gadget: configfs: Prevent buffer overrun in usb_string_copy Greg KH
2023-06-30 13:13   ` yguoaz
2023-06-30 19:48     ` Greg KH
2023-07-01  3:48       ` yguoaz

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