[PATCH 5.4.y 5.10.y 0/4] Backport of CVE-2024-44986 fix to stable 5.4 and 5.10

Following is an attempt to backport fix of CVE-2024-44986 back to stable 5.4 and 5.10. 3 extra pre-requisite patches were required to introduce the skb_expand_head() function and use it in ip6_finish_output2() for the fix patch to be applicable.

Eric Dumazet (1): ipv6: fix possible UAF in ip6_finish_output2()

Vasily Averin (3): skbuff: introduce skb_expand_head() ipv6: use skb_expand_head in ip6_finish_output2 ipv6: use skb_expand_head in ip6_xmit

include/linux/skbuff.h | 1 + net/core/skbuff.c | 42 ++++++++++++++++++++++ net/ipv6/ip6_output.c | 82 ++++++++++++++++-------------------------- 3 files changed, 74 insertions(+), 51 deletions(-)