Revert "nfp: abm: fix memory leak in nfp_abm_u32_knode_replace"

This reverts commit 78beef629fd9 ("nfp: abm: fix memory leak in
nfp_abm_u32_knode_replace").

The quoted commit does not fix anything and resulted in a bogus
CVE-2019-19076.

If match is NULL then it is known there is no matching entry in
list, hence, calling nfp_abm_u32_knode_delete() is pointless.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>

diff --git a/drivers/net/ethernet/netronome/nfp/abm/cls.c b/drivers/net/ethernet/netronome/nfp/abm/cls.c
index 9f8a1f6..23ebddf 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/abm/cls.c
+++ b/drivers/net/ethernet/netronome/nfp/abm/cls.c
@@ -176,10 +176,8 @@ nfp_abm_u32_knode_replace(struct nfp_abm_link *alink,
        u8 mask, val;
        int err;
 
-       if (!nfp_abm_u32_check_knode(alink->abm, knode, proto, extack)) {
-               err = -EOPNOTSUPP;
+       if (!nfp_abm_u32_check_knode(alink->abm, knode, proto, extack))
                goto err_delete;
-       }
 
        tos_off = proto == htons(ETH_P_IP) ? 16 : 20;
 
@@ -200,18 +198,14 @@ nfp_abm_u32_knode_replace(struct nfp_abm_link *alink,
                if ((iter->val & cmask) == (val & cmask) &&
                    iter->band != knode->res->classid) {
                        NL_SET_ERR_MSG_MOD(extack, "conflict with already offloaded filter");
-                       err = -EOPNOTSUPP;
                        goto err_delete;
                }
        }
 
        if (!match) {
                match = kzalloc(sizeof(*match), GFP_KERNEL);
-               if (!match) {
-                       err = -ENOMEM;
-                       goto err_delete;
-               }
-
+               if (!match)
+                       return -ENOMEM;
                list_add(&match->list, &alink->dscp_map);
        }
        match->handle = knode->handle;
@@ -227,7 +221,7 @@ nfp_abm_u32_knode_replace(struct nfp_abm_link *alink,
 
 err_delete:
        nfp_abm_u32_knode_delete(alink, knode);
-       return err;
+       return -EOPNOTSUPP;
 }
 
 static int nfp_abm_setup_tc_block_cb(enum tc_setup_type type,