In mlx4_en_update_priv(), dst->tx_ring[t] and dst->tx_cq[t]
are over-written by src->tx_ring[t] and src->tx_cq[t] without
first calling kfree.
One of the reproducible code paths is by doing 'ethtool -L'.
The fix is to do the kfree in mlx4_en_free_resources().
Here is the kmemleak report:
unreferenced object 0xffff880841211800 (size 2048):
comm "ethtool", pid 3096, jiffies 4294716940 (age 528.353s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81930718>] kmemleak_alloc+0x28/0x50
[<ffffffff8120b213>] kmem_cache_alloc_trace+0x103/0x260
[<ffffffff8170e0a8>] mlx4_en_try_alloc_resources+0x118/0x1a0
[<ffffffff817065a9>] mlx4_en_set_ringparam+0x169/0x210
[<ffffffff818040c5>] dev_ethtool+0xae5/0x2190
[<ffffffff8181b898>] dev_ioctl+0x168/0x6f0
[<ffffffff817d7a72>] sock_do_ioctl+0x42/0x50
[<ffffffff817d819b>] sock_ioctl+0x21b/0x2d0
[<ffffffff81247a73>] do_vfs_ioctl+0x93/0x6a0
[<ffffffff812480f9>] SyS_ioctl+0x79/0x90
[<ffffffff8193d7ea>] entry_SYSCALL_64_fastpath+0x18/0xad
[<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff880841213000 (size 2048):
comm "ethtool", pid 3096, jiffies 4294716940 (age 528.353s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81930718>] kmemleak_alloc+0x28/0x50
[<ffffffff8120b213>] kmem_cache_alloc_trace+0x103/0x260
[<ffffffff8170e0cb>] mlx4_en_try_alloc_resources+0x13b/0x1a0
[<ffffffff817065a9>] mlx4_en_set_ringparam+0x169/0x210
[<ffffffff818040c5>] dev_ethtool+0xae5/0x2190
[<ffffffff8181b898>] dev_ioctl+0x168/0x6f0
[<ffffffff817d7a72>] sock_do_ioctl+0x42/0x50
[<ffffffff817d819b>] sock_ioctl+0x21b/0x2d0
[<ffffffff81247a73>] do_vfs_ioctl+0x93/0x6a0
[<ffffffff812480f9>] SyS_ioctl+0x79/0x90
[<ffffffff8193d7ea>] entry_SYSCALL_64_fastpath+0x18/0xad
[<ffffffffffffffff>] 0xffffffffffffffff
(gdb) list *mlx4_en_try_alloc_resources+0x118
0xffffffff8170e0a8 is in mlx4_en_try_alloc_resources
(drivers/net/ethernet/mellanox/mlx4/en_netdev.c:2145).
2140 if (!dst->tx_ring_num[t])
2141 continue;
2142
2143 dst->tx_ring[t] = kzalloc(sizeof(struct mlx4_en_tx_ring
*) *
2144 MAX_TX_RINGS, GFP_KERNEL);
2145 if (!dst->tx_ring[t])
2146 goto err_free_tx;
2147
2148 dst->tx_cq[t] = kzalloc(sizeof(struct mlx4_en_cq *) *
2149 MAX_TX_RINGS, GFP_KERNEL);
(gdb) list *mlx4_en_try_alloc_resources+0x13b
0xffffffff8170e0cb is in mlx4_en_try_alloc_resources
(drivers/net/ethernet/mellanox/mlx4/en_netdev.c:2150).
2145 if (!dst->tx_ring[t])
2146 goto err_free_tx;
2147
2148 dst->tx_cq[t] = kzalloc(sizeof(struct mlx4_en_cq *) *
2149 MAX_TX_RINGS, GFP_KERNEL);
2150 if (!dst->tx_cq[t]) {
2151 kfree(dst->tx_ring[t]);
2152 goto err_free_tx;
2153 }
2154 }
Fixes: ec25bc04ed8e ("net/mlx4_en: Add resilience in low memory systems")
Cc: Eugenia Emantayev <euge...@mellanox.com>
Cc: Saeed Mahameed <sae...@mellanox.com>
Cc: Tariq Toukan <tar...@mellanox.com>
Signed-off-by: Martin KaFai Lau <ka...@fb.com>
---
drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 761f8b12399c..3abcead208d2 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -2042,6 +2042,8 @@ static void mlx4_en_free_resources(struct mlx4_en_priv
*priv)
if (priv->tx_cq[t] && priv->tx_cq[t][i])
mlx4_en_destroy_cq(priv, &priv->tx_cq[t][i]);
}
+ kfree(priv->tx_ring[t]);
+ kfree(priv->tx_cq[t]);
}
for (i = 0; i < priv->rx_ring_num; i++) {
@@ -2214,7 +2216,6 @@ void mlx4_en_destroy_netdev(struct net_device *dev)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
struct mlx4_en_dev *mdev = priv->mdev;
- int t;
en_dbg(DRV, priv, "Destroying netdev on port:%d\n", priv->port);
@@ -2248,11 +2249,6 @@ void mlx4_en_destroy_netdev(struct net_device *dev)
mlx4_en_free_resources(priv);
mutex_unlock(&mdev->state_lock);
- for (t = 0; t < MLX4_EN_NUM_TX_TYPES; t++) {
- kfree(priv->tx_ring[t]);
- kfree(priv->tx_cq[t]);
- }
-
free_netdev(dev);
}
--
2.5.1
