Commit 67d349ed authored Apr 30, 2017 by Ilan Tayari Committed by David S. Miller May 01, 2017

net/esp4: Fix invalid esph pointer crash



Both esp_output and esp_xmit take a pointer to the ESP header
and place it in esp_info struct prior to calling esp_output_head.

Inside esp_output_head, the call to esp_output_udp_encap
makes sure to update the pointer if it gets invalid.
However, if esp_output_head itself calls skb_cow_data, the
pointer is not updated and stays invalid, causing a crash
after esp_output_head returns.

Update the pointer if it becomes invalid in esp_output_head

Fixes: fca11ebd ("esp4: Reorganize esp_output")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 89a23c8b

net/ipv4/esp4.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -317,6 +317,7 @@ cow:
		if (nfrags < 0)
		goto out;
		tail = skb_tail_pointer(trailer);
		esp->esph = ip_esp_hdr(skb);

		skip_cow:
		esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);

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