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(-)
--- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1450,7 +1450,7 @@ static struct sk_buff *tun_napi_alloc_fr 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);