esp: limit skb_page_frag_refill use to a single page
Commit ebe48d36 ("esp: Fix possible buffer overflow in ESP transformation") tried to fix skb_page_frag_refill usage in ESP by capping allocsize to 32k, but that doesn't completely solve the issue, as skb_page_frag_refill may return a single page. If that happens, we will write out of bounds, despite the check introduced in the previous patch. This patch forces COW in cases where we would end up calling skb_page_frag_refill with a size larger than a page (first in esp_output_head with tailen, then in esp_output_tail with skb->data_len). Fixes: cac2661c ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by:Sabrina Dubroca <sd@queasysnail.net> Signed-off-by:
Steffen Klassert <steffen.klassert@secunet.com>
parent
748b82c2