Currently, epf_group list is traversed, and each group entry is freed and
epf_group list head is deleted in the end. Deleting the list head is
corrupting the data in the group entries that are already freed, leading to
random crashes. To fix this issue, delete each group entry and then free
it, and don't delete epf_group list head.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V2:
* Reworded the commit message

 drivers/pci/endpoint/pci-epf-core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index 9ed556936f48..a7f4ae33905d 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -340,9 +340,10 @@ static void pci_epf_remove_cfs(struct pci_epf_driver *driver)
 		return;
 
 	mutex_lock(&pci_epf_mutex);
-	list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry)
+	list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry) {
+		list_del(&group->group_entry);
 		pci_ep_cfs_remove_epf_group(group);
-	list_del(&driver->epf_group);
+	}
 	mutex_unlock(&pci_epf_mutex);
 }
 
-- 
2.17.1

On Thu, Oct 13, 2022 at 11:48:14PM +0530, Vidya Sagar wrote:
> Currently, epf_group list is traversed, and each group entry is freed and
> epf_group list head is deleted in the end. Deleting the list head is
> corrupting the data in the group entries that are already freed, leading to
> random crashes. To fix this issue, delete each group entry and then free
> it, and don't delete epf_group list head.
> 
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

Thanks,
Mani

> ---
> V2:
> * Reworded the commit message
> 
>  drivers/pci/endpoint/pci-epf-core.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
> index 9ed556936f48..a7f4ae33905d 100644
> --- a/drivers/pci/endpoint/pci-epf-core.c
> +++ b/drivers/pci/endpoint/pci-epf-core.c
> @@ -340,9 +340,10 @@ static void pci_epf_remove_cfs(struct pci_epf_driver *driver)
>  		return;
>  
>  	mutex_lock(&pci_epf_mutex);
> -	list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry)
> +	list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry) {
> +		list_del(&group->group_entry);
>  		pci_ep_cfs_remove_epf_group(group);
> -	list_del(&driver->epf_group);
> +	}
>  	mutex_unlock(&pci_epf_mutex);
>  }
>  
> -- 
> 2.17.1
> 

-- 
மணிவண்ணன் சதாசிவம்