Messages in this thread | | | Date | Wed, 08 Aug 2007 08:13:33 -0600 | From | Paul Fulghum <> | Subject | Re: Serial buffer memory leak |
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Laurent Pinchart wrote: > Patch c5c34d4862e18ef07c1276d233507f540fb5a532 (tty: flush flip buffer on > ldisc input queue flush) introduces a race condition which can lead to memory > leaks. > > The problem can be triggered when tcflush() is called when data are being > pushed to the line discipline driver by flush_to_ldisc(). > > flush_to_ldisc() releases tty->buf.lock when calling the line discipline > receive_buf function. At that poing tty_buffer_flush() kicks in and sets both > tty->buf.head and tty->buf.tail to NULL. When flush_to_ldisc() finishes, it > restores tty->buf.head but doesn't touch tty->buf.tail. This corrups the > buffer queue, and the next call to tty_buffer_request_room() will allocate a > new buffer and overwrite tty->buf.head. The previous buffer is then lost > forever without being released.
Your description is clear enough, I'll make the patch.
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