[PATCH 5.10 438/717] RDMA/mlx5: Fix MR cache memory leak

Greg Kroah-Hartman
2020-12-28T14:20:24Z

From: Maor Gottlieb <maorg@nvidia.com>

[ Upstream commit e89938902927a54abebccc9537991aca5237dfaf ]

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

Allcation backtrace for the leaker:

[<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")
Link: https://lore.kernel.org/r/20201213132940.345554-2-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 3468ae804eaee..971694e781b65 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -642,6 +642,7 @@ 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;
}

--
2.27.0