linux-kernel - [PATCH v2] usb: chipidea: add loop timeout for hw_ep_set

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210817064353.GA669425@ubuntu>
Date:   Tue, 17 Aug 2021 15:43:53 +0900
From:   Jeaho Hwang <jhhwang@...t.co.kr>
To:     Peter Chen <peter.chen@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     team-linux@...t.co.kr, mkbyeon@...lectric.co.kr,
        khchoib@...lectric.co.kr
Subject: [PATCH v2] usb: chipidea: add loop timeout for hw_ep_set_halt()

If ctrl EP priming is failed (very rare case in standard linux),
hw_ep_set_halt goes infinite loop. waiting 100 times was enough
for zynq7000.

Signed-off-by: Jeaho Hwang <jhhwang@...t.co.kr>

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 8834ca613721..d73fadb18f32 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -209,6 +209,9 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
 	return 0;
 }
 
+/* enough for zynq7000 evaluation board */
+#define HW_EP_SET_HALT_COUNT_MAX 100
+
 /**
  * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute
  *                 without interruption)
@@ -221,6 +224,7 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
  */
 static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value)
 {
+	int count = HW_EP_SET_HALT_COUNT_MAX;
 	if (value != 0 && value != 1)
 		return -EINVAL;
 
@@ -232,9 +236,9 @@ static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value)
 		/* data toggle - reserved for EP0 but it's in ESS */
 		hw_write(ci, reg, mask_xs|mask_xr,
 			  value ? mask_xs : mask_xr);
-	} while (value != hw_ep_get_halt(ci, num, dir));
+	} while (value != hw_ep_get_halt(ci, num, dir) && --count > 0);
 
-	return 0;
+	return count ? 0 : -EAGAIN;
 }
 
 /**
-- 
2.25.1