netfilter: seqadj: re-load tcp header pointer after possible head reallocation
commit5ac1f046ab4a6f629a524b9bd4f15f72bf6a4798
authorFlorian Westphal <fw@strlen.de>
Wed, 5 Dec 2018 13:12:19 +0000 (5 14:12 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 13 Jan 2019 09:00:57 +0000 (13 10:00 +0100)
treecd7c295f9b6eb7704739abceda8acaffa1e86d82
parent4ddb80f4193cf344550458087977a500a2c3cd4c
netfilter: seqadj: re-load tcp header pointer after possible head reallocation

[ Upstream commit 530aad77010b81526586dfc09130ec875cd084e4 ]

When adjusting sack block sequence numbers, skb_make_writable() gets
called to make sure tcp options are all in the linear area, and buffer
is not shared.

This can cause tcp header pointer to get reallocated, so we must
reaload it to avoid memory corruption.

This bug pre-dates git history.

Reported-by: Neel Mehta <nmehta@google.com>
Reported-by: Shane Huntley <shuntley@google.com>
Reported-by: Heather Adkins <argv@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net/netfilter/nf_conntrack_seqadj.c