[PATCH 1/2] net/bnxt/tf_core: fix ignored return of EM delete

[Denis Sergeev <denserg.edu@gmail.com>]

The return value of tfc_em_delete_raw() in tfc_em_delete() was
silently discarded: rc was unconditionally overwritten by the
subsequent tfc_cpm_get_cmm_inst() call without any error check.

If tfc_em_delete_raw() fails, the HW EM entry is not removed but
the function continues to free the corresponding SW pool entry,
creating a HW/SW state inconsistency that can lead to stale flow
matches or incorrect pool slot reuse.

Add an error check after the call and return -EINVAL on failure.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 80317ff6adfd ("net/bnxt/tf_core: support Thor2")
Cc: stable@dpdk.org

Signed-off-by: Denis Sergeev <denserg.edu@gmail.com>
---
 drivers/net/bnxt/tf_core/v3/tfc_em.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/bnxt/tf_core/v3/tfc_em.c b/drivers/net/bnxt/tf_core/v3/tfc_em.c
index 3fe4dbe3fe..4c126dc2f4 100644
--- a/drivers/net/bnxt/tf_core/v3/tfc_em.c
+++ b/drivers/net/bnxt/tf_core/v3/tfc_em.c
@@ -661,6 +661,11 @@ int tfc_em_delete(struct tfc *tfcp, struct tfc_em_delete_parms *parms)
 			       &db_offset
 #endif
 			       );
+	if (rc != 0) {
+		PMD_DRV_LOG_LINE(ERR, "tfc_em_delete_raw() failed: %s",
+				 strerror(-rc));
+		return -EINVAL;
+	}
 
 	record_offset = REMOVE_POOL_FROM_OFFSET(pi.lkup_pool_sz_exp,
 						record_offset);
-- 
2.50.1