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usb: gadget: u_serial: Add null pointer check in gserial_resume
Consider a case where gserial_disconnect has already cleared
gser->ioport. And if a wakeup interrupt triggers afterwards,
gserial_resume gets called, which will lead to accessing of
gser->ioport and thus causing null pointer dereference.Add
a null pointer check to prevent this.
Added a static spinlock to prevent gser->ioport from becoming
null after the newly added check.
Fixes: aba3a8d01d
("usb: gadget: u_serial: add suspend resume callbacks")
Cc: stable <stable@kernel.org>
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/1676309438-14922-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
7ebb605d22
commit
5ec63fdbca
1 changed files with 19 additions and 4 deletions
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@ -82,6 +82,9 @@
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#define WRITE_BUF_SIZE 8192 /* TX only */
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#define GS_CONSOLE_BUF_SIZE 8192
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/* Prevents race conditions while accessing gser->ioport */
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static DEFINE_SPINLOCK(serial_port_lock);
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/* console info */
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struct gs_console {
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struct console console;
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@ -1375,8 +1378,10 @@ void gserial_disconnect(struct gserial *gser)
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if (!port)
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return;
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spin_lock_irqsave(&serial_port_lock, flags);
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/* tell the TTY glue not to do I/O here any more */
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spin_lock_irqsave(&port->port_lock, flags);
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spin_lock(&port->port_lock);
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gs_console_disconnect(port);
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@ -1391,7 +1396,8 @@ void gserial_disconnect(struct gserial *gser)
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tty_hangup(port->port.tty);
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}
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port->suspended = false;
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spin_unlock_irqrestore(&port->port_lock, flags);
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spin_unlock(&port->port_lock);
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spin_unlock_irqrestore(&serial_port_lock, flags);
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/* disable endpoints, aborting down any active I/O */
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usb_ep_disable(gser->out);
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@ -1425,10 +1431,19 @@ EXPORT_SYMBOL_GPL(gserial_suspend);
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void gserial_resume(struct gserial *gser)
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{
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struct gs_port *port = gser->ioport;
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struct gs_port *port;
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unsigned long flags;
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spin_lock_irqsave(&port->port_lock, flags);
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spin_lock_irqsave(&serial_port_lock, flags);
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port = gser->ioport;
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if (!port) {
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spin_unlock_irqrestore(&serial_port_lock, flags);
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return;
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}
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spin_lock(&port->port_lock);
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spin_unlock(&serial_port_lock);
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port->suspended = false;
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if (!port->start_delayed) {
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spin_unlock_irqrestore(&port->port_lock, flags);
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