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authorKarsten Graul <kgraul@linux.ibm.com>2021-11-24 15:32:37 +0300
committerJakub Kicinski <kuba@kernel.org>2021-11-25 06:02:21 +0300
commit587acad41f1bc48e16f42bb2aca63bf323380be8 (patch)
treef2cdb384949c5d332d0a57aa0b0bdb7c48ffd48f /net/smc
parent06e5ba71750861acf65fb1b0cfb8f974159100af (diff)
downloadlinux-587acad41f1bc48e16f42bb2aca63bf323380be8.tar.xz
net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()
Coverity reports a possible NULL dereferencing problem: in smc_vlan_by_tcpsk(): 6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times). 7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next. 1623 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS) 8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev. 1624 if (is_vlan_dev(ndev)) { Remove the manual implementation and use netdev_walk_all_lower_dev() to iterate over the lower devices. While on it remove an obsolete function parameter comment. Fixes: cb9d43f67754 ("net/smc: determine vlan_id of stacked net_device") Suggested-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/smc')
-rw-r--r--net/smc/smc_core.c35
1 files changed, 18 insertions, 17 deletions
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 25ebd30feecd..bb52c8b5f148 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1672,14 +1672,26 @@ static void smc_link_down_work(struct work_struct *work)
mutex_unlock(&lgr->llc_conf_mutex);
}
-/* Determine vlan of internal TCP socket.
- * @vlan_id: address to store the determined vlan id into
- */
+static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
+ struct netdev_nested_priv *priv)
+{
+ unsigned short *vlan_id = (unsigned short *)priv->data;
+
+ if (is_vlan_dev(lower_dev)) {
+ *vlan_id = vlan_dev_vlan_id(lower_dev);
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Determine vlan of internal TCP socket. */
int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
{
struct dst_entry *dst = sk_dst_get(clcsock->sk);
+ struct netdev_nested_priv priv;
struct net_device *ndev;
- int i, nest_lvl, rc = 0;
+ int rc = 0;
ini->vlan_id = 0;
if (!dst) {
@@ -1697,20 +1709,9 @@ int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
goto out_rel;
}
+ priv.data = (void *)&ini->vlan_id;
rtnl_lock();
- nest_lvl = ndev->lower_level;
- for (i = 0; i < nest_lvl; i++) {
- struct list_head *lower = &ndev->adj_list.lower;
-
- if (list_empty(lower))
- break;
- lower = lower->next;
- ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
- if (is_vlan_dev(ndev)) {
- ini->vlan_id = vlan_dev_vlan_id(ndev);
- break;
- }
- }
+ netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
rtnl_unlock();
out_rel: