diff options
| author |   Pengcheng Yang <yangpc@wangsu.com> | 2019-12-30 17:54:41 +0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2020-01-02 15:42:28 -0800 |
| commit | c9655008e7845bcfdaac10a1ed8554ec167aea88 (patch) | |
| tree | 47f88a850061d17b1635abe37ab0d17238a479a5 /Documentation/networking | |
| parent | net: dsa: mv88e6xxx: force cmode write on 6141/6341 (diff) | |
| download | linux-dev-c9655008e7845bcfdaac10a1ed8554ec167aea88.tar.xz linux-dev-c9655008e7845bcfdaac10a1ed8554ec167aea88.zip | |
tcp: fix "old stuff" D-SACK causing SACK to be treated as D-SACK
When we receive a D-SACK, where the sequence number satisfies:
undo_marker <= start_seq < end_seq <= prior_snd_una
we consider this is a valid D-SACK and tcp_is_sackblock_valid()
returns true, then this D-SACK is discarded as "old stuff",
but the variable first_sack_index is not marked as negative
in tcp_sacktag_write_queue().
If this D-SACK also carries a SACK that needs to be processed
(for example, the previous SACK segment was lost), this SACK
will be treated as a D-SACK in the following processing of
tcp_sacktag_write_queue(), which will eventually lead to
incorrect updates of undo_retrans and reordering.
Fixes: fd6dad616d4f ("[TCP]: Earlier SACK block verification & simplify access to them")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
0 files changed, 0 insertions, 0 deletions