net/smc: use after free fix in smc_wr_tx_put_slot()

[ Upstream commit e438bae43c1e08e688c09c410407b59fc1c173b4 ]

In smc_wr_tx_put_slot() field pend->idx is used after being
cleared. That means always idx 0 is cleared in the wr_tx_mask.
This results in a broken administration of available WR send
payload buffers.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ursula Braun 2018-11-20 16:46:43 +01:00 committed by Greg Kroah-Hartman
parent 7ff2e42795
commit 78e6704dd6

View file

@ -215,12 +215,14 @@ int smc_wr_tx_put_slot(struct smc_link *link,
pend = container_of(wr_pend_priv, struct smc_wr_tx_pend, priv);
if (pend->idx < link->wr_tx_cnt) {
u32 idx = pend->idx;
/* clear the full struct smc_wr_tx_pend including .priv */
memset(&link->wr_tx_pends[pend->idx], 0,
sizeof(link->wr_tx_pends[pend->idx]));
memset(&link->wr_tx_bufs[pend->idx], 0,
sizeof(link->wr_tx_bufs[pend->idx]));
test_and_clear_bit(pend->idx, link->wr_tx_mask);
test_and_clear_bit(idx, link->wr_tx_mask);
return 1;
}