diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2007-02-05 09:56:15 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-02-16 15:32:19 -0800 |
| commit | db90e7a15cb4a160610b4e58576f25539ca216e7 (patch) | |
| tree | 10e0a54e3e20a42a8dd4b20448705f0ebad1dd94 | |
| parent | af59cf404fc7ad6cc642de9e78252fb264917611 (diff) | |
USB: fix concurrent buffer access in the hub driver
This patch (as849) fixes a bug in the USB hub driver. A single
pre-allocated buffer is used for all port status reads, but nothing
guarantees exclusive use of the buffer. A mutex is added to provide
this guarantee.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/core/hub.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 7d600657354..50c0db15304 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -44,6 +44,7 @@ struct usb_hub { struct usb_hub_status hub; struct usb_port_status port; } *status; /* buffer for status reports */ + struct mutex status_mutex; /* for the status buffer */ int error; /* last reported error */ int nerrors; /* track consecutive errors */ @@ -535,6 +536,7 @@ static int hub_hub_status(struct usb_hub *hub, { int ret; + mutex_lock(&hub->status_mutex); ret = get_hub_status(hub->hdev, &hub->status->hub); if (ret < 0) dev_err (hub->intfdev, @@ -544,6 +546,7 @@ static int hub_hub_status(struct usb_hub *hub, *change = le16_to_cpu(hub->status->hub.wHubChange); ret = 0; } + mutex_unlock(&hub->status_mutex); return ret; } @@ -617,6 +620,7 @@ static int hub_configure(struct usb_hub *hub, ret = -ENOMEM; goto fail; } + mutex_init(&hub->status_mutex); hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL); if (!hub->descriptor) { @@ -1396,6 +1400,7 @@ static int hub_port_status(struct usb_hub *hub, int port1, { int ret; + mutex_lock(&hub->status_mutex); ret = get_port_status(hub->hdev, port1, &hub->status->port); if (ret < 4) { dev_err (hub->intfdev, @@ -1407,6 +1412,7 @@ static int hub_port_status(struct usb_hub *hub, int port1, *change = le16_to_cpu(hub->status->port.wPortChange); ret = 0; } + mutex_unlock(&hub->status_mutex); return ret; } |