TCP has a transitional state when SACK is not in use during
which this invariant is temporarily broken. Without SACK,
tcp_clean_rtx_queue does not decrement sacked_out. Therefore
calls to tcp_sync_left_out before sacked_out is again
corrected by tcp_fastretrans_alert can trigger this trap as
sacked_out still has couple of segments that are already out
of window.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
static inline void tcp_sync_left_out(struct tcp_sock *tp)
{
- BUG_ON(tp->sacked_out + tp->lost_out > tp->packets_out);
+ BUG_ON(tp->rx_opt.sack_ok &&
+ (tp->sacked_out + tp->lost_out > tp->packets_out));
tp->left_out = tp->sacked_out + tp->lost_out;
}