isdn/gigaset: fix usb_gigaset write_cmd result race

In usb_gigaset function gigaset_write_cmd(), the length field of
the command buffer structure could be cleared by the transmit
tasklet before it was used for the function's return value.
Fix by copying to a local variable before scheduling the tasklet.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tilman Schmidt 2014-10-11 13:46:30 +02:00 committed by David S. Miller
parent 340184b35a
commit 86f8ef2c48

View File

@ -497,6 +497,7 @@ static int send_cb(struct cardstate *cs, struct cmdbuf_t *cb)
static int gigaset_write_cmd(struct cardstate *cs, struct cmdbuf_t *cb)
{
unsigned long flags;
int len;
gigaset_dbg_buffer(cs->mstate != MS_LOCKED ?
DEBUG_TRANSCMD : DEBUG_LOCKCMD,
@ -515,10 +516,11 @@ static int gigaset_write_cmd(struct cardstate *cs, struct cmdbuf_t *cb)
spin_unlock_irqrestore(&cs->cmdlock, flags);
spin_lock_irqsave(&cs->lock, flags);
len = cb->len;
if (cs->connected)
tasklet_schedule(&cs->write_tasklet);
spin_unlock_irqrestore(&cs->lock, flags);
return cb->len;
return len;
}
static int gigaset_write_room(struct cardstate *cs)