diff options
author | Willem de Bruijn <willemb@google.com> | 2019-05-15 20:29:16 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-25 19:16:12 +0300 |
commit | 912d8c4cf9f19c93dfdf06b822eeadec9d71494d (patch) | |
tree | 0bb23eff2cdf2b30553c7e054cca92d584fab7d5 /include | |
parent | 3f8c89043e4eb8f8ad58591a1b5a98be32a40991 (diff) | |
download | linux-912d8c4cf9f19c93dfdf06b822eeadec9d71494d.tar.xz |
net: test nouarg before dereferencing zerocopy pointers
[ Upstream commit 185ce5c38ea76f29b6bd9c7c8c7a5e5408834920 ]
Zerocopy skbs without completion notification were added for packet
sockets with PACKET_TX_RING user buffers. Those signal completion
through the TP_STATUS_USER bit in the ring. Zerocopy annotation was
added only to avoid premature notification after clone or orphan, by
triggering a copy on these paths for these packets.
The mechanism had to define a special "no-uarg" mode because packet
sockets already use skb_uarg(skb) == skb_shinfo(skb)->destructor_arg
for a different pointer.
Before deferencing skb_uarg(skb), verify that it is a real pointer.
Fixes: 5cd8d46ea1562 ("packet: copy user buffers before orphan or clone")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/skbuff.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 9027a8c4219f..20a4c2280308 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1425,10 +1425,12 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy) struct ubuf_info *uarg = skb_zcopy(skb); if (uarg) { - if (uarg->callback == sock_zerocopy_callback) { + if (skb_zcopy_is_nouarg(skb)) { + /* no notification callback */ + } else if (uarg->callback == sock_zerocopy_callback) { uarg->zerocopy = uarg->zerocopy && zerocopy; sock_zerocopy_put(uarg); - } else if (!skb_zcopy_is_nouarg(skb)) { + } else { uarg->callback(uarg, zerocopy); } @@ -2683,7 +2685,8 @@ static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) { if (likely(!skb_zcopy(skb))) return 0; - if (skb_uarg(skb)->callback == sock_zerocopy_callback) + if (!skb_zcopy_is_nouarg(skb) && + skb_uarg(skb)->callback == sock_zerocopy_callback) return 0; return skb_copy_ubufs(skb, gfp_mask); } |