queue-6.8/netdev-let-netlink-core-handle-emsgsize-errors.patch

   1 From f776e28a960ff183e2d35cf461c32a33bcbeb0c6 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Sat, 2 Mar 2024 21:24:07 -0800
   4 Subject: netdev: let netlink core handle -EMSGSIZE errors
   5
   6 From: Jakub Kicinski <kuba@kernel.org>
   7
   8 [ Upstream commit 0b11b1c5c320555483e8a94c44549db24c289987 ]
   9
  10 Previous change added -EMSGSIZE handling to af_netlink, we don't
  11 have to hide these errors any longer.
  12
  13 Theoretically the error handling changes from:
  14  if (err == -EMSGSIZE)
  15 to
  16  if (err == -EMSGSIZE && skb->len)
  17
  18 everywhere, but in practice it doesn't matter.
  19 All messages fit into NLMSG_GOODSIZE, so overflow of an empty
  20 skb cannot happen.
  21
  22 Reviewed-by: Eric Dumazet <edumazet@google.com>
  23 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  24 Reviewed-by: Ido Schimmel <idosch@nvidia.com>
  25 Signed-off-by: David S. Miller <davem@davemloft.net>
  26 Signed-off-by: Sasha Levin <sashal@kernel.org>
  27 ---
  28  net/core/netdev-genl.c    | 15 +++------------
  29  net/core/page_pool_user.c |  2 --
  30  2 files changed, 3 insertions(+), 14 deletions(-)
  31
  32 diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
  33 index fd98936da3aec..918b109e0cf40 100644
  34 --- a/net/core/netdev-genl.c
  35 +++ b/net/core/netdev-genl.c
  36 @@ -152,10 +152,7 @@ int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
  37         }
  38         rtnl_unlock();
  39
  40 -       if (err != -EMSGSIZE)
  41 -               return err;
  42 -
  43 -       return skb->len;
  44 +       return err;
  45  }
  46
  47  static int
  48 @@ -287,10 +284,7 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
  49         }
  50         rtnl_unlock();
  51
  52 -       if (err != -EMSGSIZE)
  53 -               return err;
  54 -
  55 -       return skb->len;
  56 +       return err;
  57  }
  58
  59  static int
  60 @@ -463,10 +457,7 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
  61         }
  62         rtnl_unlock();
  63
  64 -       if (err != -EMSGSIZE)
  65 -               return err;
  66 -
  67 -       return skb->len;
  68 +       return err;
  69  }
  70
  71  static int netdev_genl_netdevice_event(struct notifier_block *nb,
  72 diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
  73 index 278294aca66ab..3a3277ba167b1 100644
  74 --- a/net/core/page_pool_user.c
  75 +++ b/net/core/page_pool_user.c
  76 @@ -103,8 +103,6 @@ netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
  77         mutex_unlock(&page_pools_lock);
  78         rtnl_unlock();
  79
  80 -       if (skb->len && err == -EMSGSIZE)
  81 -               return skb->len;
  82         return err;
  83  }
  84
  85 --
  86 2.43.0
  87