skbuff: Call skb_zcopy_clear() before unref'ing fragments

mainline inclusion
from mainline-v5.12-rc1-dontuse
commit 70c43167
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4CVS3
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=70c4316749f6

----------------------------------------------------------------------

RX zerocopy fragment pages which are not allocated from the
system page pool require special handling.  Give the callback
in skb_zcopy_clear() a chance to process them first.
Signed-off-by: NJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NYongxin Li <liyongxin1@huawei.com>
Signed-off-by: NJunxin Chen <chenjunxin1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/core/skbuff.c

@@ -614,13 +614,14 @@ static void skb_release_data(struct sk_buff *skb)
 			      &shinfo->dataref))
 		return;
 
+	skb_zcopy_clear(skb, true);
+
 	for (i = 0; i < shinfo->nr_frags; i++)
 		__skb_frag_unref(&shinfo->frags[i]);
 
 	if (shinfo->frag_list)
 		kfree_skb_list(shinfo->frag_list);
 
-	skb_zcopy_clear(skb, true);
 	skb_free_head(skb);
 }