Re: [PATCH v2 3/7] dmaengine: idxd: fix memory leak in error handling path of idxd_setup_groups

From: Fenghua Yu
Date: Tue Feb 18 2025 - 15:20:28 EST


Hi, Shuai,

On 2/14/25 21:44, Shuai Xue wrote:
Memory allocated for groups is not freed if an error occurs during
idxd_setup_groups(). To fix it, free the allocated memory in the reverse
order of allocation before exiting the function in case of an error.

Fixes: defe49f96012 ("dmaengine: idxd: fix group conf_dev lifetime")
Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
drivers/dma/idxd/init.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 4e47075c5bef..a2da68e6144d 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -328,6 +328,7 @@ static int idxd_setup_groups(struct idxd_device *idxd)
rc = dev_set_name(conf_dev, "group%d.%d", idxd->id, group->id);
if (rc < 0) {
put_device(conf_dev);
+ kfree(group);
goto err;
}
@@ -352,7 +353,10 @@ static int idxd_setup_groups(struct idxd_device *idxd)
while (--i >= 0) {
group = idxd->groups[i];
put_device(group_confdev(group));
+ kfree(group);
}
+ kfree(idxd->groups);
+

What happens to the memory areas previously allocated for wqs and engines after idxd_setup_groups() fails? They need to be freed as well, but currently they are not.

Maybe a separate patch cleans up the previously allocated mem areas for wqs/engines/groups if there is any failure after the allocations?



return rc;
}

Thanks.


-Fenghua