From c17ff6ec3b69ef228047bf346e0b524c48d2c96e Mon Sep 17 00:00:00 2001 From: Florin Coras Date: Wed, 22 Apr 2020 22:07:43 +0000 Subject: [PATCH] tcp: avoid bt sample access after possible pool realloc Type: fix Signed-off-by: Florin Coras Change-Id: I98f943c8862fa74fb576f9ec1fb9186289b1216b --- src/vnet/tcp/tcp_bt.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/src/vnet/tcp/tcp_bt.c b/src/vnet/tcp/tcp_bt.c index eaec147b836..9c255fa0dc9 100644 --- a/src/vnet/tcp/tcp_bt.c +++ b/src/vnet/tcp/tcp_bt.c @@ -340,6 +340,7 @@ tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end) tcp_bt_sample_t *bts, *next, *cur, *prev, *nbts; u32 bts_index, cur_index, next_index, prev_index, max_seq; u8 is_end = end == tc->snd_nxt; + tcp_bts_flags_t bts_flags; /* Contiguous blocks retransmitted at the same time */ bts = bt_get_sample (bt, bt->last_ooo); @@ -354,8 +355,10 @@ tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end) return; } - /* Find original tx sample */ + /* Find original tx sample and cache flags in case the sample + * is freed or the pool moves */ bts = bt_lookup_seq (bt, start); + bts_flags = bts->flags; ASSERT (bts != 0 && seq_geq (start, bts->min_seq)); @@ -366,12 +369,9 @@ tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end) /* Head overlap */ if (bts->min_seq == start) { - /* bts can be freed by bt_fix_overlapped() below */ - tcp_bts_flags_t bts_flags = bts->flags; - prev_index = bts->prev; next = bt_fix_overlapped (bt, bts, end, is_end); - /* bts is no longer valid from here */ + /* bts might no longer be valid from here */ next_index = bt_sample_index (bt, next); cur = tcp_bt_alloc_tx_sample (tc, start, end); @@ -418,7 +418,7 @@ tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end) /* Have to split or tail overlap */ cur = tcp_bt_alloc_tx_sample (tc, start, end); cur->flags |= TCP_BTS_IS_RXT; - if (bts->flags & TCP_BTS_IS_RXT) + if (bts_flags & TCP_BTS_IS_RXT) cur->flags |= TCP_BTS_IS_RXT_LOST; cur->prev = bts_index; cur_index = bt_sample_index (bt, cur); -- 2.16.6