From ab4e6ee578e88a659938db8fbf33720bc048d29c Mon Sep 17 00:00:00 2001 From: Brandon Maier Date: Tue, 26 Jun 2018 12:50:48 -0500 Subject: [PATCH] net: phy: xgmiitorgmii: Check phy_driver ready before accessing Since a phy_device is added to the global mdio_bus list during phy_device_register(), but a phy_device's phy_driver doesn't get attached until phy_probe(). It's possible of_phy_find_device() in xgmiitorgmii will return a valid phy with a NULL phy_driver. Leading to a NULL pointer access during the memcpy(). Fixes this Oops: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.40 #1 Hardware name: Xilinx Zynq Platform task: ce4c8d00 task.stack: ce4ca000 PC is at memcpy+0x48/0x330 LR is at xgmiitorgmii_probe+0x90/0xe8 pc : [] lr : [] psr: 20000013 sp : ce4cbb54 ip : 00000000 fp : ce4cbb8c r10: 00000000 r9 : 00000000 r8 : c0c49178 r7 : 00000000 r6 : cdc14718 r5 : ce762800 r4 : cdc14710 r3 : 00000000 r2 : 00000054 r1 : 00000000 r0 : cdc14718 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 18c5387d Table: 0000404a DAC: 00000051 Process swapper/0 (pid: 1, stack limit = 0xce4ca210) ... [] (memcpy) from [] (xgmiitorgmii_probe+0x90/0xe8) [] (xgmiitorgmii_probe) from [] (mdio_probe+0x28/0x34) [] (mdio_probe) from [] (driver_probe_device+0x254/0x414) [] (driver_probe_device) from [] (__device_attach_driver+0xac/0x10c) [] (__device_attach_driver) from [] (bus_for_each_drv+0x84/0xc8) [] (bus_for_each_drv) from [] (__device_attach+0xd0/0x134) [] (__device_attach) from [] (device_initial_probe+0x1c/0x20) [] (device_initial_probe) from [] (bus_probe_device+0x98/0xa0) [] (bus_probe_device) from [] (device_add+0x43c/0x5d0) [] (device_add) from [] (mdio_device_register+0x34/0x80) [] (mdio_device_register) from [] (of_mdiobus_register+0x170/0x30c) [] (of_mdiobus_register) from [] (macb_probe+0x710/0xc00) [] (macb_probe) from [] (platform_drv_probe+0x44/0x80) [] (platform_drv_probe) from [] (driver_probe_device+0x254/0x414) [] (driver_probe_device) from [] (__driver_attach+0x10c/0x118) [] (__driver_attach) from [] (bus_for_each_dev+0x8c/0xd0) [] (bus_for_each_dev) from [] (driver_attach+0x2c/0x30) [] (driver_attach) from [] (bus_add_driver+0x50/0x260) [] (bus_add_driver) from [] (driver_register+0x88/0x108) [] (driver_register) from [] (__platform_driver_register+0x50/0x58) [] (__platform_driver_register) from [] (macb_driver_init+0x24/0x28) [] (macb_driver_init) from [] (do_one_initcall+0x60/0x1a4) [] (do_one_initcall) from [] (kernel_init_freeable+0x15c/0x1f8) [] (kernel_init_freeable) from [] (kernel_init+0x18/0x124) [] (kernel_init) from [] (ret_from_fork+0x14/0x20) Code: ba000002 f5d1f03c f5d1f05c f5d1f07c (e8b151f8) ---[ end trace 3e4ec21905820a1f ]--- Signed-off-by: Brandon Maier Reviewed-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/xilinx_gmii2rgmii.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c index 2e5150b0b8d5..04c8bec1c4c1 100644 --- a/drivers/net/phy/xilinx_gmii2rgmii.c +++ b/drivers/net/phy/xilinx_gmii2rgmii.c @@ -81,6 +81,11 @@ static int xgmiitorgmii_probe(struct mdio_device *mdiodev) return -EPROBE_DEFER; } + if (!priv->phy_dev->drv) { + dev_info(dev, "Attached phy not ready\n"); + return -EPROBE_DEFER; + } + priv->addr = mdiodev->addr; priv->phy_drv = priv->phy_dev->drv; memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,