[PATCH rdma-rc 1/5] RDMA/mlx5: Fix MR cache memory leak

[Leon Romanovsky <leon@kernel.org>]

From: Maor Gottlieb <maorg@nvidia.com>

If the MR cache entry invalidation failed, then we detach this entry
from the cache, therefore we must to free the memory as well.

  comm "python3", pid 15325, jiffies 4298483783 (age 1787.596s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 40 62 12 f4 82 88 ff ff  ........b……
    00 22 08 00 00 22 08 00 00 00 00 00 00 00 00 00  .“…”……….

  backtrace:

    [<00000000d8e423b0>] alloc_cache_mr+0x23/0xc0 [mlx5_ib]
    [<000000001f21304c>] create_cache_mr+0x3f/0xf0 [mlx5_ib]
    [<000000009d6b45dc>] mlx5_ib_alloc_implicit_mr+0x41/0×210 [mlx5_ib]
    [<00000000879d0d68>] mlx5_ib_reg_user_mr+0x9e/0×6e0 [mlx5_ib]
    [<00000000be74bf89>] create_qp+0x2fc/0xf00 [ib_uverbs]
    [<000000001a532d22>] ib_uverbs_handler_UVERBS_METHOD_COUNTERS_READ+0x1d9/0×230 [ib_uverbs]
    [<0000000070f46001>] rdma_alloc_commit_uobject+0xb5/0×120 [ib_uverbs]
    [<000000006d8a0b38>] uverbs_alloc+0x2b/0xf0 [ib_uverbs]
    [<00000000075217c9>] ksysioctl+0x234/0×7d0
    [<00000000eb5c120b>] __x64_sys_ioctl+0x16/0×20
    [<00000000db135b48>] do_syscall_64+0x59/0×2e0

Fixes: 1769c4c57548 ("RDMA/mlx5: Always remove MRs from the cache before destroying them")
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/hw/mlx5/mr.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index 80e3047110a8..479543ebf697 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -644,6 +644,7 @@ void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
 	if (mlx5_mr_cache_invalidate(mr)) {
 		detach_mr_from_cache(mr);
 		destroy_mkey(dev, mr);
+		kfree(mr);
 		return;
 	}

--
2.29.2