From da29e4b466e6916a52e0e2f60054f855c324a9c2 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 3 Jun 2019 15:16:58 -0700 Subject: [PATCH] net/tls: fully initialize the msg wrapper skb If strparser gets cornered into starting a new message from an sk_buff which already has frags, it will allocate a new skb to become the "wrapper" around the fragments of the message. This new skb does not inherit any metadata fields. In case of TLS offload this may lead to unnecessarily re-encrypting the message, as skb->decrypted is not set for the wrapper skb. Try to be conservative and copy all fields of old skb strparser's user may reasonably need. Signed-off-by: Jakub Kicinski Reviewed-by: Dirk van der Merwe Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 25 +++++++++++++++++++++++++ net/strparser/strparser.c | 8 ++------ 3 files changed, 28 insertions(+), 6 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2ee5e63195c0..98ff5ac98caa 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1063,6 +1063,7 @@ struct sk_buff *alloc_skb_with_frags(unsigned long header_len, int max_page_order, int *errcode, gfp_t gfp_mask); +struct sk_buff *alloc_skb_for_msg(struct sk_buff *first); /* Layout of fast clones : [skb1][skb2][fclone_ref] */ struct sk_buff_fclones { diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 4a712a00243a..b50a5e3ac4e4 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -913,6 +913,31 @@ static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb) #undef C } +/** + * alloc_skb_for_msg() - allocate sk_buff to wrap frag list forming a msg + * @first: first sk_buff of the msg + */ +struct sk_buff *alloc_skb_for_msg(struct sk_buff *first) +{ + struct sk_buff *n; + + n = alloc_skb(0, GFP_ATOMIC); + if (!n) + return NULL; + + n->len = first->len; + n->data_len = first->len; + n->truesize = first->truesize; + + skb_shinfo(n)->frag_list = first; + + __copy_skb_header(n, first); + n->destructor = NULL; + + return n; +} +EXPORT_SYMBOL_GPL(alloc_skb_for_msg); + /** * skb_morph - morph one skb into another * @dst: the skb to receive the contents diff --git a/net/strparser/strparser.c b/net/strparser/strparser.c index e137698e8aef..3fe541b746b0 100644 --- a/net/strparser/strparser.c +++ b/net/strparser/strparser.c @@ -160,18 +160,14 @@ static int __strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb, return 0; } - skb = alloc_skb(0, GFP_ATOMIC); + skb = alloc_skb_for_msg(head); if (!skb) { STRP_STATS_INCR(strp->stats.mem_fail); desc->error = -ENOMEM; return 0; } - skb->len = head->len; - skb->data_len = head->len; - skb->truesize = head->truesize; - *_strp_msg(skb) = *_strp_msg(head); + strp->skb_nextp = &head->next; - skb_shinfo(skb)->frag_list = head; strp->skb_head = skb; head = skb; } else { -- 2.30.2