Hi Andrew,
On Wed, May 4, 2022 at 11:31 AM Fabio Estevam festevam@gmail.com wrote:
From: Fabio Estevam festevam@denx.de
Since commit f1131b9c23fb ("net: phy: micrel: use kszphy_suspend()/kszphy_resume for irq aware devices") the following NULL pointer dereference is observed on a board with KSZ8061:
# udhcpc -i eth0 udhcpc: started, v1.35.0 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000008 pgd = f73cef4e [00000008] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 PID: 196 Comm: ifconfig Not tainted 5.15.37-dirty #94 Hardware name: Freescale i.MX6 SoloX (Device Tree) PC is at kszphy_config_reset+0x10/0x114 LR is at kszphy_resume+0x24/0x64 ...
The KSZ8061 phy_driver structure does not have the .probe/..driver_data fields, which means that priv is not allocated.
This causes the NULL pointer dereference inside kszphy_config_reset().
Fix the problem by using the generic suspend/resume functions as before.
Another alternative would be to provide the .probe and .driver_data information into the structure, but to be on the safe side, let's just restore Ethernet functionality by using the generic suspend/resume.
Cc: stable@vger.kernel.org Fixes: f1131b9c23fb ("net: phy: micrel: use kszphy_suspend()/kszphy_resume for irq aware devices") Signed-off-by: Fabio Estevam festevam@denx.de
Changes since v1:
- Explained why enphy_suspend/resume solution is preferred (Andrew).
If this series gets applied, I plan to submit two patches targeting net-next to:
1. Allow .probe to be called without .data_driver being passed 2. Convert KSZ8061 to use .probe and kszphy_suspend/resume