Messages in this thread | | | Date | Thu, 16 May 2013 10:05:18 -0400 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH] tty_buffer: avoid race due to tty_buffer_free_all() being misused |
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On Thu, May 16, 2013 at 04:59:22PM +0800, channing wrote: > > In tty_buffer.c, function tty_buffer_free_all() is used to remove > all buffers for a tty, although it's declared that it mustn't be called > when the tty is in use, it cannot guarantee that. we can observe some > device driver make use it by mistake, for example, while tty device is > releasing, the tty data forwarding is not stopped, then it might hit > the case that tty buffer is being used while tty_buffer_free_all() > free this tty buffer, and finally lead to random error at any places, > and it's not clear to debug. > > Although device driver could do better, it's simpler and safer to > strengthen protection in the view of tty buffer, by adding a tty->buf.lock > in tty_buffer_free_all() to avoid it racing with ongoing tty buffer > operations. > > Signed-off-by: channing <chao.bi@intel.com>
Note, in the future, I need a "full" name for a signed-off-by: line and From line in the patch.
thanks,
greg k-h
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