tipc: fix bug in broadcast retransmit code
In commit 58dc55f2 ("tipc: use generic SKB list APIs to manage link transmission queue") we replace all list traversal loops with the macros skb_queue_walk() or skb_queue_walk_safe(). While the previous loops were based on the assumption that the list was NULL-terminated, the standard macros stop when the iterator reaches the list head, which is non-NULL. In the function bclink_retransmit_pkt() this macro replacement has lead to a bug. When we receive a BCAST STATE_MSG we unconditionally call the function bclink_retransmit_pkt(), whether there really is anything to retransmit or not, assuming that the sequence number comparisons will lead to the correct behavior. However, if the transmission queue is empty, or if there are no eligible buffers in the transmission queue, we will by mistake pass the list head pointer to the function tipc_link_retransmit(). Since the list head is not a valid sk_buff, this leads to a crash. In this commit we fix this by only calling tipc_link_retransmit() if we actually found eligible buffers in the transmission queue. Reviewed-by:Ying Xue <ying.xue@windriver.com> Signed-off-by:
Jon Maloy <jon.maloy@ericsson.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
45e81834
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