5.15-stable review patch. If anyone has any objections, please let me know.
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From: Jann Horn jannh@google.com
[ Upstream commit c8e7ff41f819b0c31c66c5196933c26c18f7681f ]
The flag uhid->running can be set to false by uhid_device_add_worker() without holding the uhid->devlock. Mark all reads/writes of the flag that might race with READ_ONCE()/WRITE_ONCE() for clarity and correctness.
Signed-off-by: Jann Horn jannh@google.com Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hid/uhid.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index ba0ca652b9dab..09da654d2b05c 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -84,7 +84,7 @@ static void uhid_device_add_worker(struct work_struct *work) * However, we do have to clear the ->running flag and do a * wakeup to make sure userspace knows that the device is gone. */ - uhid->running = false; + WRITE_ONCE(uhid->running, false); wake_up_interruptible(&uhid->report_wait); } } @@ -194,9 +194,9 @@ static int __uhid_report_queue_and_wait(struct uhid_device *uhid, spin_unlock_irqrestore(&uhid->qlock, flags);
ret = wait_event_interruptible_timeout(uhid->report_wait, - !uhid->report_running || !uhid->running, + !uhid->report_running || !READ_ONCE(uhid->running), 5 * HZ); - if (!ret || !uhid->running || uhid->report_running) + if (!ret || !READ_ONCE(uhid->running) || uhid->report_running) ret = -EIO; else if (ret < 0) ret = -ERESTARTSYS; @@ -237,7 +237,7 @@ static int uhid_hid_get_report(struct hid_device *hid, unsigned char rnum, struct uhid_event *ev; int ret;
- if (!uhid->running) + if (!READ_ONCE(uhid->running)) return -EIO;
ev = kzalloc(sizeof(*ev), GFP_KERNEL); @@ -279,7 +279,7 @@ static int uhid_hid_set_report(struct hid_device *hid, unsigned char rnum, struct uhid_event *ev; int ret;
- if (!uhid->running || count > UHID_DATA_MAX) + if (!READ_ONCE(uhid->running) || count > UHID_DATA_MAX) return -EIO;
ev = kzalloc(sizeof(*ev), GFP_KERNEL); @@ -580,7 +580,7 @@ static int uhid_dev_destroy(struct uhid_device *uhid) if (!uhid->hid) return -EINVAL;
- uhid->running = false; + WRITE_ONCE(uhid->running, false); wake_up_interruptible(&uhid->report_wait);
cancel_work_sync(&uhid->worker); @@ -594,7 +594,7 @@ static int uhid_dev_destroy(struct uhid_device *uhid)
static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) { - if (!uhid->running) + if (!READ_ONCE(uhid->running)) return -EINVAL;
hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data, @@ -605,7 +605,7 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev) { - if (!uhid->running) + if (!READ_ONCE(uhid->running)) return -EINVAL;
hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data, @@ -617,7 +617,7 @@ static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev) static int uhid_dev_get_report_reply(struct uhid_device *uhid, struct uhid_event *ev) { - if (!uhid->running) + if (!READ_ONCE(uhid->running)) return -EINVAL;
uhid_report_wake_up(uhid, ev->u.get_report_reply.id, ev); @@ -627,7 +627,7 @@ static int uhid_dev_get_report_reply(struct uhid_device *uhid, static int uhid_dev_set_report_reply(struct uhid_device *uhid, struct uhid_event *ev) { - if (!uhid->running) + if (!READ_ONCE(uhid->running)) return -EINVAL;
uhid_report_wake_up(uhid, ev->u.set_report_reply.id, ev);