On 3/14/2024 10:36 AM, Mingjin Ye wrote:
Inserting a vdev device when the device arguments are already stored
in devargs_list, the rte_devargs_insert function replaces the supplied
new devargs with the found devargs and frees the new devargs. As a
result, the use of free devargs results in a core dump.
This patch fixes the issue by using valid devargs.
Fixes: f3a1188cee4a ("devargs: make device representation generic")
Cc: sta...@dpdk.org
Signed-off-by: Mingjin Ye <mingjinx...@intel.com>
I am not too familiar with how devargs works, so I have a trivial question.
I understand the point of this patch, and it is roughly as follows:
1) we enter insert_vdev and allocated new devargs structure (and copy
the `name` into devargs)
2) we set dev->device.name to devargs->name
3) we insert devargs into the list using rte_devargs_insert
4) if devargs list already had devargs with the same name, our devargs
is destroyed and replaced with devargs that is in the list
5) because of this, dev->device.name becomes invalid as that specific
devargs has been freed - it points to name from the old devargs
We do need to store devargs->name in dev->device.name, and we need to do
so after calling rte_devargs_insert to avoid keeping reference to memory
that was freed. So, provisionally,
Reviewed-by: Anatoly Burakov <anatoly.bura...@intel.com>
My question is, under what circumstances would there be duplicate
entries in devargs list? I assume there is an answer to that question
because rte_devargs_insert() expects this case, so this is just for my
understanding - I can't seem to figure out how we would arrive at a
situation where we have duplicate devargs.
---
drivers/bus/vdev/vdev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index 1a6cc7d12d..53fc4a6e21 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -286,7 +286,6 @@ insert_vdev(const char *name, const char *args, struct
rte_vdev_device **p_dev)
dev->device.bus = &rte_vdev_bus;
dev->device.numa_node = SOCKET_ID_ANY;
- dev->device.name = devargs->name;
if (find_vdev(name)) {
/*
@@ -300,6 +299,7 @@ insert_vdev(const char *name, const char *args, struct
rte_vdev_device **p_dev)
rte_devargs_insert(&devargs);
dev->device.devargs = devargs;
+ dev->device.name = devargs->name;
TAILQ_INSERT_TAIL(&vdev_device_list, dev, next);
if (p_dev)
--
Thanks,
Anatoly
