[PATCH 6.7 55/61] net: pds_core: Fix possible double free in error handling path

From: Sasha Levin
Date: Wed Mar 13 2024 - 12:45:38 EST


From: Yongzhi Liu <hyperlyzcs@xxxxxxxxx>

[ Upstream commit ba18deddd6d502da71fd6b6143c53042271b82bd ]

When auxiliary_device_add() returns error and then calls
auxiliary_device_uninit(), Callback function pdsc_auxbus_dev_release
calls kfree(padev) to free memory. We shouldn't call kfree(padev)
again in the error handling path.

Fix this by cleaning up the redundant kfree() and putting
the error handling back to where the errors happened.

Fixes: 4569cce43bc6 ("pds_core: add auxiliary_bus devices")
Signed-off-by: Yongzhi Liu <hyperlyzcs@xxxxxxxxx>
Reviewed-by: Wojciech Drewek <wojciech.drewek@xxxxxxxxx>
Reviewed-by: Shannon Nelson <shannon.nelson@xxxxxxx>
Link: https://lore.kernel.org/r/20240306105714.20597-1-hyperlyzcs@xxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/amd/pds_core/auxbus.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/amd/pds_core/auxbus.c b/drivers/net/ethernet/amd/pds_core/auxbus.c
index 11c23a7f3172d..fd1a5149c0031 100644
--- a/drivers/net/ethernet/amd/pds_core/auxbus.c
+++ b/drivers/net/ethernet/amd/pds_core/auxbus.c
@@ -160,23 +160,19 @@ static struct pds_auxiliary_dev *pdsc_auxbus_dev_register(struct pdsc *cf,
if (err < 0) {
dev_warn(cf->dev, "auxiliary_device_init of %s failed: %pe\n",
name, ERR_PTR(err));
- goto err_out;
+ kfree(padev);
+ return ERR_PTR(err);
}

err = auxiliary_device_add(aux_dev);
if (err) {
dev_warn(cf->dev, "auxiliary_device_add of %s failed: %pe\n",
name, ERR_PTR(err));
- goto err_out_uninit;
+ auxiliary_device_uninit(aux_dev);
+ return ERR_PTR(err);
}

return padev;
-
-err_out_uninit:
- auxiliary_device_uninit(aux_dev);
-err_out:
- kfree(padev);
- return ERR_PTR(err);
}

int pdsc_auxbus_dev_del(struct pdsc *cf, struct pdsc *pf)
--
2.43.0