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authorDavid Vrabel <david.vrabel@citrix.com>2013-02-14 03:18:57 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-02-28 05:38:40 -0800
commit8f56788f8d42ce5b5888ab7e9e7270646bcacd48 (patch)
tree93838dbfb5b5727050ccd3cdd4c5e7e36ceee0f3
parent8d33ee7534d7d8c0ee9f0aa5aad2fa4522463671 (diff)
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xen-netback: correctly return errors from netbk_count_requests()
[ Upstream commit 35876b5ffc154c357476b2c3bdab10feaf4bd8f0 ] netbk_count_requests() could detect an error, call netbk_fatal_tx_error() but return 0. The vif may then be used afterwards (e.g., in a call to netbk_tx_error(). Since netbk_fatal_tx_error() could set vif->refcnt to 1, the vif may be freed immediately after the call to netbk_fatal_tx_error() (e.g., if the vif is also removed). Netback thread Xenwatch thread ------------------------------------------- netbk_fatal_tx_err() netback_remove() xenvif_disconnect() ... free_netdev() netbk_tx_err() Oops! Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reported-by: Christopher S. Aker <caker@theshore.net> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/xen-netback/netback.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 2b9520c46e97..cd49ba949636 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -911,13 +911,13 @@ static int netbk_count_requests(struct xenvif *vif,
if (frags >= work_to_do) {
netdev_err(vif->dev, "Need more frags\n");
netbk_fatal_tx_err(vif);
- return -frags;
+ return -ENODATA;
}
if (unlikely(frags >= MAX_SKB_FRAGS)) {
netdev_err(vif->dev, "Too many frags\n");
netbk_fatal_tx_err(vif);
- return -frags;
+ return -E2BIG;
}
memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + frags),
@@ -925,7 +925,7 @@ static int netbk_count_requests(struct xenvif *vif,
if (txp->size > first->size) {
netdev_err(vif->dev, "Frag is bigger than frame.\n");
netbk_fatal_tx_err(vif);
- return -frags;
+ return -EIO;
}
first->size -= txp->size;
@@ -935,7 +935,7 @@ static int netbk_count_requests(struct xenvif *vif,
netdev_err(vif->dev, "txp->offset: %x, size: %u\n",
txp->offset, txp->size);
netbk_fatal_tx_err(vif);
- return -frags;
+ return -EINVAL;
}
} while ((txp++)->flags & XEN_NETTXF_more_data);
return frags;