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.
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 --- drivers/net/phy/micrel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index 685a0ab5453c..11cd073630e5 100644 --- a/drivers/net/phy/micrel.c +++ b/drivers/net/phy/micrel.c @@ -3021,8 +3021,8 @@ static struct phy_driver ksphy_driver[] = { .config_init = ksz8061_config_init, .config_intr = kszphy_config_intr, .handle_interrupt = kszphy_handle_interrupt, - .suspend = kszphy_suspend, - .resume = kszphy_resume, + .suspend = genphy_suspend, + .resume = genphy_resume, }, { .phy_id = PHY_ID_KSZ9021, .phy_id_mask = 0x000ffffe,
On Wed, May 04, 2022 at 08:47:03AM -0300, Fabio Estevam 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.
Hi Fabio
Thanks for the fix. What you fail to mention is why not call kszphy_probe() to populate priv? What makes this PHY special that it does not need the probe call?
Looking at the ksphy_driver structure, this seems to affect PHY_ID_KS8737 and PHY_ID_KSZ8061
Thanks Andrew
Hi Andrew,
On Wed, May 4, 2022 at 9:19 AM Andrew Lunn andrew@lunn.ch wrote:
Thanks for the fix. What you fail to mention is why not call kszphy_probe() to populate priv? What makes this PHY special that it does not need the probe call?
Looking at the driver history, it has been like this since the beginning.
Adding kszphy_probe() only causes another NULL pointer dereference.
I would need to add both kszphy_probe() and driver_data.
Both can be added, but I don't think this would be material for stable.
I would not like to add a wrong driver_data and cause other problems.
IMHO, I would prefer to restore the Ethernet functionality first, then if someone is certain on the proper driver data, this could be added to net-next.
Looking at the ksphy_driver structure, this seems to affect PHY_ID_KS8737 and PHY_ID_KSZ8061
Good catch, thanks.
ksz8737 has a .driver_data field, so I can add .driver_probe there.
For v2 I plan:
- Send two patch as a series:
patch 1/2 would be same as this one patch 2/2 would pass driver_probe to ksz8737
Do you agree?
Thanks
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