From: Ilya Lesokhin <ilyal@mellanox.com>
Date: Mon, 30 Apr 2018 10:16:11 +0300
Subject: net: Rename and export copy_skb_header
Patch-mainline: v4.18-rc1
Git-commit: 08303c189581c985e60f588ad92a041e46b6e307
References: bsc#1200762, CVE-2022-33741, XSA-403

copy_skb_header is renamed to skb_copy_header and
exported. Exposing this function give more flexibility
in copying SKBs.
skb_copy and skb_copy_expand do not give enough control
over which parts are copied.

Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/linux/skbuff.h |    1 +
 net/core/skbuff.c      |    9 +++++----
 2 files changed, 6 insertions(+), 4 deletions(-)

--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -956,6 +956,7 @@ static inline struct sk_buff *alloc_skb_
 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
+void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
 				   gfp_t gfp_mask, bool fclone);
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1045,7 +1045,7 @@ static void skb_headers_offset_update(st
 	skb->inner_mac_header += off;
 }
 
-static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
+void skb_copy_header(struct sk_buff *new, const struct sk_buff *old)
 {
 	__copy_skb_header(new, old);
 
@@ -1053,6 +1053,7 @@ static void copy_skb_header(struct sk_bu
 	skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs;
 	skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type;
 }
+EXPORT_SYMBOL(skb_copy_header);
 
 static inline int skb_alloc_rx_flag(const struct sk_buff *skb)
 {
@@ -1096,7 +1097,7 @@ struct sk_buff *skb_copy(const struct sk
 	if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len))
 		BUG();
 
-	copy_skb_header(n, skb);
+	skb_copy_header(n, skb);
 	return n;
 }
 EXPORT_SYMBOL(skb_copy);
@@ -1159,7 +1160,7 @@ struct sk_buff *__pskb_copy_fclone(struc
 		skb_clone_fraglist(n);
 	}
 
-	copy_skb_header(n, skb);
+	skb_copy_header(n, skb);
 out:
 	return n;
 }
@@ -1340,7 +1341,7 @@ struct sk_buff *skb_copy_expand(const st
 			  skb->len + head_copy_len))
 		BUG();
 
-	copy_skb_header(n, skb);
+	skb_copy_header(n, skb);
 
 	skb_headers_offset_update(n, newheadroom - oldheadroom);