Commit 9cc00b51 authored by John Fastabend's avatar John Fastabend Committed by Jeff Kirsher

ixgbe: ethtool: stats user buffer overrun

If the number of tx/rx queues changes the ethtool ioctl
ETHTOOL_GSTATS may overrun the userspace buffer. This
occurs because the general practice in user space to
query stats is to issue a ETHTOOL_GSSET cmd to learn the
buffer size needed, allocate the buffer, then call
ETHTOOL_GSTIRNGS and ETHTOOL_GSTATS. If the number of
real_num_queues is changed or flow control attributes
are changed after ETHTOOL_GSSET but before the
ETHTOOL_GSTRINGS/ETHTOOL_GSTATS a user space buffer
overrun occurs.

To fix the overrun always return the max buffer size
needed from get_sset_count() then return all strings
and stats from get_strings()/get_ethtool_stats().

This _will_ change the output from the ioctl() call
which could break applications and script parsing in
theory. I believe these changes should not break existing
tools because the only changes will be more {tx|rx}_queues
and the {tx|rx}_pb_* stats will always be returned.
Existing scripts already need to handle changing number
of queues because this occurs today depending on system
and current features. The {tx|rx}_pb_* stats are at the
end of the output and should be handled by scripts today
regardless.

Finally get_ethtool_stats and get_strings are free-form
outputs tools parsing these outputs should be defensive
anyways. In the end these updates are better then
having a tool segfault because of a buffer overrun.
Signed-off-by: default avatarJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 5facb8e0
......@@ -120,19 +120,23 @@ static const struct ixgbe_stats ixgbe_gstrings_stats[] = {
#endif /* IXGBE_FCOE */
};
#define IXGBE_QUEUE_STATS_LEN \
((((struct ixgbe_adapter *)netdev_priv(netdev))->num_tx_queues + \
((struct ixgbe_adapter *)netdev_priv(netdev))->num_rx_queues) * \
/* ixgbe allocates num_tx_queues and num_rx_queues symmetrically so
* we set the num_rx_queues to evaluate to num_tx_queues. This is
* used because we do not have a good way to get the max number of
* rx queues with CONFIG_RPS disabled.
*/
#define IXGBE_NUM_RX_QUEUES netdev->num_tx_queues
#define IXGBE_QUEUE_STATS_LEN ( \
(netdev->num_tx_queues + IXGBE_NUM_RX_QUEUES) * \
(sizeof(struct ixgbe_queue_stats) / sizeof(u64)))
#define IXGBE_GLOBAL_STATS_LEN ARRAY_SIZE(ixgbe_gstrings_stats)
#define IXGBE_PB_STATS_LEN ( \
(((struct ixgbe_adapter *)netdev_priv(netdev))->flags & \
IXGBE_FLAG_DCB_ENABLED) ? \
(sizeof(((struct ixgbe_adapter *)0)->stats.pxonrxc) + \
sizeof(((struct ixgbe_adapter *)0)->stats.pxontxc) + \
sizeof(((struct ixgbe_adapter *)0)->stats.pxoffrxc) + \
sizeof(((struct ixgbe_adapter *)0)->stats.pxofftxc)) \
/ sizeof(u64) : 0)
/ sizeof(u64))
#define IXGBE_STATS_LEN (IXGBE_GLOBAL_STATS_LEN + \
IXGBE_PB_STATS_LEN + \
IXGBE_QUEUE_STATS_LEN)
......@@ -1078,8 +1082,15 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev,
data[i] = (ixgbe_gstrings_stats[i].sizeof_stat ==
sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
}
for (j = 0; j < adapter->num_tx_queues; j++) {
for (j = 0; j < IXGBE_NUM_RX_QUEUES; j++) {
ring = adapter->tx_ring[j];
if (!ring) {
data[i] = 0;
data[i+1] = 0;
i += 2;
continue;
}
do {
start = u64_stats_fetch_begin_bh(&ring->syncp);
data[i] = ring->stats.packets;
......@@ -1087,8 +1098,15 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev,
} while (u64_stats_fetch_retry_bh(&ring->syncp, start));
i += 2;
}
for (j = 0; j < adapter->num_rx_queues; j++) {
for (j = 0; j < IXGBE_NUM_RX_QUEUES; j++) {
ring = adapter->rx_ring[j];
if (!ring) {
data[i] = 0;
data[i+1] = 0;
i += 2;
continue;
}
do {
start = u64_stats_fetch_begin_bh(&ring->syncp);
data[i] = ring->stats.packets;
......@@ -1096,22 +1114,20 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev,
} while (u64_stats_fetch_retry_bh(&ring->syncp, start));
i += 2;
}
if (adapter->flags & IXGBE_FLAG_DCB_ENABLED) {
for (j = 0; j < MAX_TX_PACKET_BUFFERS; j++) {
for (j = 0; j < IXGBE_MAX_PACKET_BUFFERS; j++) {
data[i++] = adapter->stats.pxontxc[j];
data[i++] = adapter->stats.pxofftxc[j];
}
for (j = 0; j < MAX_RX_PACKET_BUFFERS; j++) {
for (j = 0; j < IXGBE_MAX_PACKET_BUFFERS; j++) {
data[i++] = adapter->stats.pxonrxc[j];
data[i++] = adapter->stats.pxoffrxc[j];
}
}
}
static void ixgbe_get_strings(struct net_device *netdev, u32 stringset,
u8 *data)
{
struct ixgbe_adapter *adapter = netdev_priv(netdev);
char *p = (char *)data;
int i;
......@@ -1126,32 +1142,30 @@ static void ixgbe_get_strings(struct net_device *netdev, u32 stringset,
ETH_GSTRING_LEN);
p += ETH_GSTRING_LEN;
}
for (i = 0; i < adapter->num_tx_queues; i++) {
for (i = 0; i < netdev->num_tx_queues; i++) {
sprintf(p, "tx_queue_%u_packets", i);
p += ETH_GSTRING_LEN;
sprintf(p, "tx_queue_%u_bytes", i);
p += ETH_GSTRING_LEN;
}
for (i = 0; i < adapter->num_rx_queues; i++) {
for (i = 0; i < IXGBE_NUM_RX_QUEUES; i++) {
sprintf(p, "rx_queue_%u_packets", i);
p += ETH_GSTRING_LEN;
sprintf(p, "rx_queue_%u_bytes", i);
p += ETH_GSTRING_LEN;
}
if (adapter->flags & IXGBE_FLAG_DCB_ENABLED) {
for (i = 0; i < MAX_TX_PACKET_BUFFERS; i++) {
for (i = 0; i < IXGBE_MAX_PACKET_BUFFERS; i++) {
sprintf(p, "tx_pb_%u_pxon", i);
p += ETH_GSTRING_LEN;
sprintf(p, "tx_pb_%u_pxoff", i);
p += ETH_GSTRING_LEN;
}
for (i = 0; i < MAX_RX_PACKET_BUFFERS; i++) {
for (i = 0; i < IXGBE_MAX_PACKET_BUFFERS; i++) {
sprintf(p, "rx_pb_%u_pxon", i);
p += ETH_GSTRING_LEN;
sprintf(p, "rx_pb_%u_pxoff", i);
p += ETH_GSTRING_LEN;
}
}
/* BUG_ON(p - data != IXGBE_STATS_LEN * ETH_GSTRING_LEN); */
break;
}
......
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