From: Saeed Mahameed <saeedm@xxxxxxxxxxxx> [ Upstream commit 31634bf5dcc418b5b2cacd954394c0c4620db6a2 ] To avoid use-after-free, hold the rcu read lock until we are done copying flow data into the command buffer. Fixes: ab412e1dd7db ("net/mlx5: Accel, add TLS rx offload routines") Reported-by: Eric Dumazet <eric.dumazet@xxxxxxxxx> Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c @@ -217,22 +217,22 @@ int mlx5_fpga_tls_resync_rx(struct mlx5_ void *cmd; int ret; - rcu_read_lock(); - flow = idr_find(&mdev->fpga->tls->rx_idr, ntohl(handle)); - rcu_read_unlock(); - - if (!flow) { - WARN_ONCE(1, "Received NULL pointer for handle\n"); - return -EINVAL; - } - buf = kzalloc(size, GFP_ATOMIC); if (!buf) return -ENOMEM; cmd = (buf + 1); + rcu_read_lock(); + flow = idr_find(&mdev->fpga->tls->rx_idr, ntohl(handle)); + if (unlikely(!flow)) { + rcu_read_unlock(); + WARN_ONCE(1, "Received NULL pointer for handle\n"); + kfree(buf); + return -EINVAL; + } mlx5_fpga_tls_flow_to_cmd(flow, cmd); + rcu_read_unlock(); MLX5_SET(tls_cmd, cmd, swid, ntohl(handle)); MLX5_SET64(tls_cmd, cmd, tls_rcd_sn, be64_to_cpu(rcd_sn));