From: Oliver Neukum Date: Thu, 8 Aug 2019 09:28:54 +0000 (+0200) Subject: Revert "USB: rio500: simplify locking" X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=2ca359f4f8b954b3a9d15a89f22a8b7283e7669f;p=openwrt%2Fstaging%2Fblogic.git Revert "USB: rio500: simplify locking" This reverts commit d710734b06770814de2bfa2819420fb5df7f3a81. This simplification causes a deadlock. Reported-by: syzbot+7bbcbe9c9ff0cd49592a@syzkaller.appspotmail.com Fixes: d710734b0677 ("USB: rio500: simplify locking") Cc: stable Signed-off-by: Oliver Neukum Link: https://lore.kernel.org/r/20190808092854.23519-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/misc/rio500.c b/drivers/usb/misc/rio500.c index 27e9c78a791e..a32d61a79ab8 100644 --- a/drivers/usb/misc/rio500.c +++ b/drivers/usb/misc/rio500.c @@ -51,6 +51,7 @@ struct rio_usb_data { char *obuf, *ibuf; /* transfer buffers */ char bulk_in_ep, bulk_out_ep; /* Endpoint assignments */ wait_queue_head_t wait_q; /* for timeouts */ + struct mutex lock; /* general race avoidance */ }; static DEFINE_MUTEX(rio500_mutex); @@ -62,8 +63,10 @@ static int open_rio(struct inode *inode, struct file *file) /* against disconnect() */ mutex_lock(&rio500_mutex); + mutex_lock(&(rio->lock)); if (rio->isopen || !rio->present) { + mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex); return -EBUSY; } @@ -71,6 +74,7 @@ static int open_rio(struct inode *inode, struct file *file) init_waitqueue_head(&rio->wait_q); + mutex_unlock(&(rio->lock)); dev_info(&rio->rio_dev->dev, "Rio opened.\n"); mutex_unlock(&rio500_mutex); @@ -84,6 +88,7 @@ static int close_rio(struct inode *inode, struct file *file) /* against disconnect() */ mutex_lock(&rio500_mutex); + mutex_lock(&(rio->lock)); rio->isopen = 0; if (!rio->present) { @@ -95,6 +100,7 @@ static int close_rio(struct inode *inode, struct file *file) } else { dev_info(&rio->rio_dev->dev, "Rio closed.\n"); } + mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex); return 0; } @@ -109,7 +115,7 @@ static long ioctl_rio(struct file *file, unsigned int cmd, unsigned long arg) int retries; int retval=0; - mutex_lock(&rio500_mutex); + mutex_lock(&(rio->lock)); /* Sanity check to make sure rio is connected, powered, etc */ if (rio->present == 0 || rio->rio_dev == NULL) { retval = -ENODEV; @@ -253,7 +259,7 @@ static long ioctl_rio(struct file *file, unsigned int cmd, unsigned long arg) err_out: - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return retval; } @@ -273,12 +279,12 @@ write_rio(struct file *file, const char __user *buffer, int errn = 0; int intr; - intr = mutex_lock_interruptible(&rio500_mutex); + intr = mutex_lock_interruptible(&(rio->lock)); if (intr) return -EINTR; /* Sanity check to make sure rio is connected, powered, etc */ if (rio->present == 0 || rio->rio_dev == NULL) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return -ENODEV; } @@ -301,7 +307,7 @@ write_rio(struct file *file, const char __user *buffer, goto error; } if (signal_pending(current)) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return bytes_written ? bytes_written : -EINTR; } @@ -339,12 +345,12 @@ write_rio(struct file *file, const char __user *buffer, buffer += copy_size; } while (count > 0); - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return bytes_written ? bytes_written : -EIO; error: - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return errn; } @@ -361,12 +367,12 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos) char *ibuf; int intr; - intr = mutex_lock_interruptible(&rio500_mutex); + intr = mutex_lock_interruptible(&(rio->lock)); if (intr) return -EINTR; /* Sanity check to make sure rio is connected, powered, etc */ if (rio->present == 0 || rio->rio_dev == NULL) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return -ENODEV; } @@ -377,11 +383,11 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos) while (count > 0) { if (signal_pending(current)) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return read_count ? read_count : -EINTR; } if (!rio->rio_dev) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return -ENODEV; } this_read = (count >= IBUF_SIZE) ? IBUF_SIZE : count; @@ -399,7 +405,7 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos) count = this_read = partial; } else if (result == -ETIMEDOUT || result == 15) { /* FIXME: 15 ??? */ if (!maxretry--) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); dev_err(&rio->rio_dev->dev, "read_rio: maxretry timeout\n"); return -ETIME; @@ -409,19 +415,19 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos) finish_wait(&rio->wait_q, &wait); continue; } else if (result != -EREMOTEIO) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); dev_err(&rio->rio_dev->dev, "Read Whoops - result:%d partial:%u this_read:%u\n", result, partial, this_read); return -EIO; } else { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return (0); } if (this_read) { if (copy_to_user(buffer, ibuf, this_read)) { - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return -EFAULT; } count -= this_read; @@ -429,7 +435,7 @@ read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos) buffer += this_read; } } - mutex_unlock(&rio500_mutex); + mutex_unlock(&(rio->lock)); return read_count; } @@ -494,6 +500,8 @@ static int probe_rio(struct usb_interface *intf, } dev_dbg(&intf->dev, "ibuf address:%p\n", rio->ibuf); + mutex_init(&(rio->lock)); + usb_set_intfdata (intf, rio); rio->present = 1; bail_out: @@ -511,10 +519,12 @@ static void disconnect_rio(struct usb_interface *intf) if (rio) { usb_deregister_dev(intf, &usb_rio_class); + mutex_lock(&(rio->lock)); if (rio->isopen) { rio->isopen = 0; /* better let it finish - the release will do whats needed */ rio->rio_dev = NULL; + mutex_unlock(&(rio->lock)); mutex_unlock(&rio500_mutex); return; } @@ -524,6 +534,7 @@ static void disconnect_rio(struct usb_interface *intf) dev_info(&intf->dev, "USB Rio disconnected.\n"); rio->present = 0; + mutex_unlock(&(rio->lock)); } mutex_unlock(&rio500_mutex); }