diff options
| -rw-r--r-- | net/core/skbuff.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index cc3b4b70288b..609f2c7f4a47 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -6832,6 +6832,34 @@ failure: } EXPORT_SYMBOL(alloc_skb_with_frags); +/* pskb_carve_inside_header() and pskb_carve_inside_nonlinear() + * remove the first bytes of a packet and reallocate skb->head. + * + * Whatever headers were present before the operation are gone, + * we must not leave stale offsets, otherwise users of this skb + * (skb_dump(), drop_monitor, taps, ...) would read or pull garbage. + */ +static void skb_carve_reset_headers(struct sk_buff *skb) +{ + skb_unset_mac_header(skb); + skb_unset_transport_header(skb); + skb_reset_network_header(skb); + skb->mac_len = 0; + + /* Inner offsets have no "unset" marker, zero them so that + * skb_inner_network_header_was_set() becomes false and no + * consumer mistakes them for a real (and long gone) header. + */ + skb->inner_mac_header = 0; + skb->inner_network_header = 0; + skb->inner_transport_header = 0; + skb->inner_protocol = 0; + skb->encapsulation = 0; + + if (skb->ip_summed == CHECKSUM_PARTIAL) + skb->ip_summed = CHECKSUM_NONE; +} + /* carve out the first off bytes from skb when off < headlen */ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, const int headlen, gfp_t gfp_mask) @@ -6887,7 +6915,7 @@ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, skb->head_frag = 0; skb_set_end_offset(skb, size); skb_set_tail_pointer(skb, skb_headlen(skb)); - skb_headers_offset_update(skb, 0); + skb_carve_reset_headers(skb); skb->cloned = 0; skb->hdr_len = 0; skb->nohdr = 0; @@ -7027,7 +7055,7 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, skb->data = data; skb_set_end_offset(skb, size); skb_reset_tail_pointer(skb); - skb_headers_offset_update(skb, 0); + skb_carve_reset_headers(skb); skb->cloned = 0; skb->hdr_len = 0; skb->nohdr = 0; |