From: zhuyan <zhuyan34@huawei.com>
To: <gregkh@linuxfoundation.org>, <anton@enomsg.org>
Cc: <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<zhuyan34@huawei.com>
Subject: [PATCH] usb:host: fix divide-by-zero in function fhci_queue_urb
Date: Tue, 9 Apr 2019 22:37:12 +0800 [thread overview]
Message-ID: <1554820632-13782-1-git-send-email-zhuyan34@huawei.com> (raw)
In function fhci_queue_urb, the divisor of expression
(urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe,
usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results
may occur, so it is necessary to ensure that the divisor is not zero.
Signed-off-by: zhuyan <zhuyan34@huawei.com>
---
drivers/usb/host/fhci-sched.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c
index 3d12cdd..27ed63c 100644
--- a/drivers/usb/host/fhci-sched.c
+++ b/drivers/usb/host/fhci-sched.c
@@ -704,6 +704,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
struct td *td;
u8 *data;
u16 cnt = 0;
+ u16 max_pkt_size = 0;
if (ed == NULL) {
ed = fhci_get_empty_ed(fhci);
@@ -765,11 +766,13 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb)
switch (ed->mode) {
case FHCI_TF_BULK:
+ max_pkt_size = usb_maxpacket(urb->dev, urb->pipe,
+ usb_pipeout(urb->pipe));
if (urb->transfer_flags & URB_ZERO_PACKET &&
urb->transfer_buffer_length > 0 &&
+ (max_pkt_size != 0) &&
((urb->transfer_buffer_length %
- usb_maxpacket(urb->dev, urb->pipe,
- usb_pipeout(urb->pipe))) == 0))
+ max_pkt_size) == 0))
urb_state = US_BULK0;
while (data_len > 4096) {
td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt,
--
1.8.5.6
next reply other threads:[~2019-04-09 14:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-09 14:37 zhuyan [this message]
2019-04-16 9:45 ` [PATCH] usb:host: fix divide-by-zero in function fhci_queue_urb Greg KH
2019-04-16 14:48 zhuyan (M)
2019-04-16 15:07 ` Alan Stern
2019-04-17 7:09 zhuyan (M)
2019-04-17 13:45 ` Alan Stern
2019-04-17 15:33 zhuyan (M)
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