From f32b20e89e82c9ff1825fc5c5d69753ff5558ccd Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 31 Jan 2017 22:35:32 -0800 Subject: [PATCH] mlx4: Fix memory leak after mlx4_en_update_priv() 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: [] kmemleak_alloc+0x28/0x50 [] kmem_cache_alloc_trace+0x103/0x260 [] mlx4_en_try_alloc_resources+0x118/0x1a0 [] mlx4_en_set_ringparam+0x169/0x210 [] dev_ethtool+0xae5/0x2190 [] dev_ioctl+0x168/0x6f0 [] sock_do_ioctl+0x42/0x50 [] sock_ioctl+0x21b/0x2d0 [] do_vfs_ioctl+0x93/0x6a0 [] SyS_ioctl+0x79/0x90 [] entry_SYSCALL_64_fastpath+0x18/0xad [] 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: [] kmemleak_alloc+0x28/0x50 [] kmem_cache_alloc_trace+0x103/0x260 [] mlx4_en_try_alloc_resources+0x13b/0x1a0 [] mlx4_en_set_ringparam+0x169/0x210 [] dev_ethtool+0xae5/0x2190 [] dev_ioctl+0x168/0x6f0 [] sock_do_ioctl+0x42/0x50 [] sock_ioctl+0x21b/0x2d0 [] do_vfs_ioctl+0x93/0x6a0 [] SyS_ioctl+0x79/0x90 [] entry_SYSCALL_64_fastpath+0x18/0xad [] 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 Cc: Saeed Mahameed Cc: Tariq Toukan Signed-off-by: Martin KaFai Lau Reviewed-by: Tariq Toukan Signed-off-by: David S. Miller --- 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); } -- 2.20.1