From e438bae43c1e08e688c09c410407b59fc1c173b4 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Tue, 20 Nov 2018 16:46:43 +0100 Subject: [PATCH] net/smc: use after free fix in smc_wr_tx_put_slot() 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 Signed-off-by: David S. Miller --- net/smc/smc_wr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c index 3c458d279855..c2694750a6a8 100644 --- a/net/smc/smc_wr.c +++ b/net/smc/smc_wr.c @@ -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; }