diff options
| author | Willem de Bruijn | 2021-06-09 18:41:57 -0400 |
|---|---|---|
| committer | David S. Miller | 2021-06-10 13:39:57 -0700 |
| commit | 3bdd5ee0ec8c14131d560da492e6df452c6fdd75 (patch) | |
| tree | 7570089040ba20cd29843991e4bdd5c35a0812b9 /net | |
| parent | 388fa7f13d61074ba3aaedce0f47ff92441c0b1a (diff) | |
skbuff: fix incorrect msg_zerocopy copy notifications
msg_zerocopy signals if a send operation required copying with a flag
in serr->ee.ee_code.
This field can be incorrect as of the below commit, as a result of
both structs uarg and serr pointing into the same skb->cb[].
uarg->zerocopy must be read before skb->cb[] is reinitialized to hold
serr. Similar to other fields len, hi and lo, use a local variable to
temporarily hold the value.
This was not a problem before, when the value was passed as a function
argument.
Fixes: 75518851a2a0 ("skbuff: Push status and refcounts into sock_zerocopy_callback")
Reported-by: Talal Ahmad <talalahmad@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/skbuff.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3ad22870298c..bbc3b4b62032 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1253,6 +1253,7 @@ static void __msg_zerocopy_callback(struct ubuf_info *uarg) struct sock *sk = skb->sk; struct sk_buff_head *q; unsigned long flags; + bool is_zerocopy; u32 lo, hi; u16 len; @@ -1267,6 +1268,7 @@ static void __msg_zerocopy_callback(struct ubuf_info *uarg) len = uarg->len; lo = uarg->id; hi = uarg->id + len - 1; + is_zerocopy = uarg->zerocopy; serr = SKB_EXT_ERR(skb); memset(serr, 0, sizeof(*serr)); @@ -1274,7 +1276,7 @@ static void __msg_zerocopy_callback(struct ubuf_info *uarg) serr->ee.ee_origin = SO_EE_ORIGIN_ZEROCOPY; serr->ee.ee_data = hi; serr->ee.ee_info = lo; - if (!uarg->zerocopy) + if (!is_zerocopy) serr->ee.ee_code |= SO_EE_CODE_ZEROCOPY_COPIED; q = &sk->sk_error_queue; |