This is a note to let you know that I've just added the patch titled
usb: gadget: f_hid: fixed NULL pointer dereference
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 2867652e4766360adf14dfda3832455e04964f2a Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@xxxxxxxxxxxxxxx>
Date: Fri, 23 Jul 2021 18:59:30 +0300
Subject: usb: gadget: f_hid: fixed NULL pointer dereference
Disconnecting and reconnecting the USB cable can lead to crashes
and a variety of kernel log spam.
The problem was found and reproduced on the Raspberry Pi [1]
and the original fix was created in Raspberry's own fork [2].
Link: https://github.com/raspberrypi/linux/issues/3870 [1]
Link: https://github.com/raspberrypi/linux/commit/a6e47d5f4efbd2ea6a0b6565cd2f9b7bb217ded5 [2]
Signed-off-by: Maxim Devaev <mdevaev@xxxxxxxxx>
Signed-off-by: Phil Elwell <phil@xxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210723155928.210019-1-mdevaev@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/f_hid.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 02683ac0719d..08e73e8127b1 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -338,6 +338,11 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
spin_lock_irqsave(&hidg->write_spinlock, flags);
+ if (!hidg->req) {
+ spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+ return -ESHUTDOWN;
+ }
+
#define WRITE_COND (!hidg->write_pending)
try_again:
/* write queue */
@@ -358,8 +363,14 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
count = min_t(unsigned, count, hidg->report_length);
spin_unlock_irqrestore(&hidg->write_spinlock, flags);
- status = copy_from_user(req->buf, buffer, count);
+ if (!req) {
+ ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
+ status = -ESHUTDOWN;
+ goto release_write_pending;
+ }
+
+ status = copy_from_user(req->buf, buffer, count);
if (status != 0) {
ERROR(hidg->func.config->cdev,
"copy_from_user error\n");
@@ -387,14 +398,17 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+ if (!hidg->in_ep->enabled) {
+ ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
+ status = -ESHUTDOWN;
+ goto release_write_pending;
+ }
+
status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
- if (status < 0) {
- ERROR(hidg->func.config->cdev,
- "usb_ep_queue error on int endpoint %zd\n", status);
+ if (status < 0)
goto release_write_pending;
- } else {
+ else
status = count;
- }
return status;
release_write_pending:
--
2.32.0
