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| author | Eric Dumazet <edumazet@google.com> | 2017-01-27 16:11:27 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-01-27 18:03:29 +0100 |
| commit | 158f323b9868b59967ad96957c4ca388161be321 (patch) | |
| tree | 507829772e7f0849038baf503f85fe788b0e4340 /net/wireless | |
| parent | Merge branch 'sfc-encapsulated-filters' (diff) | |
| download | linux-158f323b9868b59967ad96957c4ca388161be321.tar.xz linux-158f323b9868b59967ad96957c4ca388161be321.zip | |
net: adjust skb->truesize in pskb_expand_head()
Slava Shwartsman reported a warning in skb_try_coalesce(), when we
detect skb->truesize is completely wrong.
In his case, issue came from IPv6 reassembly coping with malicious
datagrams, that forced various pskb_may_pull() to reallocate a bigger
skb->head than the one allocated by NIC driver before entering GRO
layer.
Current code does not change skb->truesize, leaving this burden to
callers if they care enough.
Blindly changing skb->truesize in pskb_expand_head() is not
easy, as some producers might track skb->truesize, for example
in xmit path for back pressure feedback (sk->sk_wmem_alloc)
We can detect the cases where it should be safe to change
skb->truesize :
1) skb is not attached to a socket.
2) If it is attached to a socket, destructor is sock_edemux()
My audit gave only two callers doing their own skb->truesize
manipulation.
I had to remove skb parameter in sock_edemux macro when
CONFIG_INET is not set to avoid a compile error.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Slava Shwartsman <slavash@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/wireless')
| -rw-r--r-- | net/wireless/util.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/wireless/util.c b/net/wireless/util.c index 1b9296882dcd..68e5f2ecee1a 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -618,8 +618,6 @@ int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr, if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC)) return -ENOMEM; - - skb->truesize += head_need; } if (encaps_data) { |