From: Roland Dreier <roland@purestorage.com>
Date: Mon, 15 Jan 2018 12:24:49 -0800
Subject: qed: Fix potential use-after-free in qed_spq_post()
Patch-mainline: v4.15-rc9
Git-commit: 70eeff66c4696cee4076d6388b6bede5bd7ff71c
References: bsc#1086314 FATE#324886 bsc#1086313 FATE#324885 bsc#1086301 FATE#3248881
We need to check if p_ent->comp_mode is QED_SPQ_MODE_EBLOCK before
calling qed_spq_add_entry(). The test is fine is the mode is EBLOCK,
but if it isn't then qed_spq_add_entry() might kfree(p_ent).
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/qlogic/qed/qed_spq.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/qlogic/qed/qed_spq.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_spq.c
@@ -776,6 +776,7 @@ int qed_spq_post(struct qed_hwfn *p_hwfn
int rc = 0;
struct qed_spq *p_spq = p_hwfn ? p_hwfn->p_spq : NULL;
bool b_ret_ent = true;
+ bool eblock;
if (!p_hwfn)
return -EINVAL;
@@ -794,6 +795,11 @@ int qed_spq_post(struct qed_hwfn *p_hwfn
if (rc)
goto spq_post_fail;
+ /* Check if entry is in block mode before qed_spq_add_entry,
+ * which might kfree p_ent.
+ */
+ eblock = (p_ent->comp_mode == QED_SPQ_MODE_EBLOCK);
+
/* Add the request to the pending queue */
rc = qed_spq_add_entry(p_hwfn, p_ent, p_ent->priority);
if (rc)
@@ -811,7 +817,7 @@ int qed_spq_post(struct qed_hwfn *p_hwfn
spin_unlock_bh(&p_spq->lock);
- if (p_ent->comp_mode == QED_SPQ_MODE_EBLOCK) {
+ if (eblock) {
/* For entries in QED BLOCK mode, the completion code cannot
* perform the necessary cleanup - if it did, we couldn't
* access p_ent here to see whether it's successful or not.