[PATCH] phy_ethtool_{sset,gset} -- check phydev for NULL

[Matvejchikov Ilya]

Good Day!

The command 'brctl addbr br0 eth0' brings the kernel oops if the eth0
has PHY, but the phydev is NULL (for ex., ifconfig eth0 0.0.0.0 was
not issued firstly)

Call Trace:
[C02CFBD0] [7FFFFFFF] 0x7fffffff (unreliable)
[C02CFBE0] [C0109634] dev_ethtool+0x1b0/0xfac
[C02CFCD0] [C0155EF0] port_cost+0x5c/0x130
[C02CFD40] [C01561FC] br_add_if+0x17c/0x308
[C02CFD70] [C01569E0] add_del_if+0x70/0xa0
[C02CFD90] [C0156A58] br_dev_ioctl+0x48/0x9fc
[C02CFE10] [C0106FCC] dev_ifsioc+0x144/0x3ac
[C02CFE30] [C01080D8] dev_ioctl+0x3b8/0x4c8
[C02CFEB0] [C00F9BC0] sock_ioctl+0x78/0x260
[C02CFED0] [C006889C] do_ioctl+0x38/0x84
[C02CFEE0] [C006896C] vfs_ioctl+0x84/0x3d8
[C02CFF10] [C0068D00] sys_ioctl+0x40/0x74
[C02CFF40] [C000EF48] ret_from_syscall+0x0/0x38

The following patch fixes the problem.

Signed-off-by: Matvejchikov Ilya <matvejchikov <at> gmail.com>

===================================================================
diff -purN linux-2.6.21-clean/drivers/net/phy/phy.c
linux-2.6.21/drivers/net/phy/phy.c
--- linux-2.6.21-clean/drivers/net/phy/phy.c	2007-04-26 07:08:32.000000000 +0400
+++ linux-2.6.21/drivers/net/phy/phy.c	2007-05-04 08:22:01.000000000 +0400
@@ -245,6 +245,9 @@ EXPORT_SYMBOL(phy_sanitize_settings);
  */
  int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 {
+	if (unlikely(NULL == phydev))
+		return -EINVAL;
+
  	if (cmd->phy_address != phydev->addr)
  		return -EINVAL;

@@ -289,6 +292,9 @@ EXPORT_SYMBOL(phy_ethtool_sset);

  int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 {
+	if (unlikely(NULL == phydev))
+		return -EINVAL;
+
  	cmd->supported = phydev->supported;

  	cmd->advertising = phydev->advertising;