From: Yunjian Wang <wangyunjian@huawei.com> [ Upstream commit 950271d7cc0b4546af3549d8143c4132d6e1f138 ] Currently the tun_napi_alloc_frags() function returns -ENOMEM when the number of iovs exceeds MAX_SKB_FRAGS + 1. However this is inappropriate, we should use -EMSGSIZE instead of -ENOMEM. The following distinctions are matters: 1. the caller need to drop the bad packet when -EMSGSIZE is returned, which means meeting a persistent failure. 2. the caller can try again when -ENOMEM is returned, which means meeting a transient failure. Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Yunjian Wang <wangyunjian@huawei.com> Acked-by: Willem de Bruijn <willemb@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/1608864736-24332-1-git-send-email-wangyunjian@huaw... Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/tun.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 008bdd186344..66d024b0ce5e 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1450,7 +1450,7 @@ static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile, int i; if (it->nr_segs > MAX_SKB_FRAGS + 1) - return ERR_PTR(-ENOMEM); + return ERR_PTR(-EMSGSIZE); local_bh_disable(); skb = napi_get_frags(&tfile->napi); -- 2.25.1