[dpdk-dev] [PATCH 4/8] ipc: fix vfio memleak

[dpdk-dev] [PATCH 4/8] ipc: fix vfio memleak

[Herakliusz Lipiec]

When sending multiple requests, rte_mp_request_sync
can succeed sending a few of those requests, but then
fail on a later one and in the end return with rc=-1.
The upper layers - e.g. device hotplug - currently
handles this case as if no messages were sent and no
memory for response buffers was allocated, which is
not true. Fixed by always freeing reply message buffers.

Fixes: 83a73c5fef66 ("vfio: use generic multi-process channel")
Cc: jianfeng.tan@intel.com
Cc: stable@dpdk.org
Signed-off-by: Herakliusz Lipiec <herakliusz.lipiec@intel.com>
---
 lib/librte_eal/linux/eal/eal_vfio.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/librte_eal/linux/eal/eal_vfio.c b/lib/librte_eal/linux/eal/eal_vfio.c
index 19e70bb66..d293df062 100644
--- a/lib/librte_eal/linux/eal/eal_vfio.c
+++ b/lib/librte_eal/linux/eal/eal_vfio.c
@@ -319,8 +319,8 @@ vfio_open_group_fd(int iommu_group_num)
 			RTE_LOG(ERR, EAL, "  bad VFIO group fd\n");
 			vfio_group_fd = 0;
 		}
-		free(mp_reply.msgs);
 	}
+	free(mp_reply.msgs);
 
 	if (vfio_group_fd < 0)
 		RTE_LOG(ERR, EAL, "  cannot request group fd\n");
@@ -583,8 +583,8 @@ vfio_sync_default_container(void)
 		p = (struct vfio_mp_param *)mp_rep->param;
 		if (p->result == SOCKET_OK)
 			iommu_type_id = p->iommu_type_id;
-		free(mp_reply.msgs);
 	}
+	free(mp_reply.msgs);
 	if (iommu_type_id < 0) {
 		RTE_LOG(ERR, EAL, "Could not get IOMMU type for default container\n");
 		return -1;
@@ -1050,8 +1050,8 @@ vfio_get_default_container_fd(void)
 			free(mp_reply.msgs);
 			return mp_rep->fds[0];
 		}
-		free(mp_reply.msgs);
 	}
+	free(mp_reply.msgs);
 
 	RTE_LOG(ERR, EAL, "  cannot request default container fd\n");
 	return -1;
@@ -1182,8 +1182,8 @@ rte_vfio_get_container_fd(void)
 			free(mp_reply.msgs);
 			return vfio_container_fd;
 		}
-		free(mp_reply.msgs);
 	}
+	free(mp_reply.msgs);
 
 	RTE_LOG(ERR, EAL, "  cannot request container fd\n");
 	return -1;
-- 
2.17.2

Re: [dpdk-dev] [PATCH 4/8] ipc: fix vfio memleak

[Burakov, Anatoly]

On 17-Apr-19 3:41 PM, Herakliusz Lipiec wrote:
> When sending multiple requests, rte_mp_request_sync
> can succeed sending a few of those requests, but then
> fail on a later one and in the end return with rc=-1.
> The upper layers - e.g. device hotplug - currently
> handles this case as if no messages were sent and no
> memory for response buffers was allocated, which is
> not true. Fixed by always freeing reply message buffers.

This commit message is duplicated in multiple commits, and does not 
really describe the problem you're fixing. Since you've already updated 
the IPC API docs to ask caller to free even in case of failure, i think 
here (and in other similar patches) it is sufficient to just say 
something like:

When sending synchronous IPC requests, the caller must free the response 
buffer even if the request returned failure. Fix the code to correctly 
use the IPC API.

> 
> Fixes: 83a73c5fef66 ("vfio: use generic multi-process channel")
> Cc: jianfeng.tan@intel.com
> Cc: stable@dpdk.org
> Signed-off-by: Herakliusz Lipiec <herakliusz.lipiec@intel.com>
> ---

For actual code,

Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

-- 
Thanks,
Anatoly