5.10-stable review patch. If anyone has any objections, please let me know.
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From: Sergej Bauer sbauer@blackbox.su
[ Upstream commit e9e13b6adc338be1eb88db87bcb392696144bd02 ]
This is the 3rd revision of the patch fix for potential null pointer dereference with lan743x card.
The simpliest way to reproduce: boot with bare lan743x and issue "ethtool ethN" commant where ethN is the interface with lan743x card. Example:
$ sudo ethtool eth7 dmesg: [ 103.510336] BUG: kernel NULL pointer dereference, address: 0000000000000340 ... [ 103.510836] RIP: 0010:phy_ethtool_get_wol+0x5/0x30 [libphy] ... [ 103.511629] Call Trace: [ 103.511666] lan743x_ethtool_get_wol+0x21/0x40 [lan743x] [ 103.511724] dev_ethtool+0x1507/0x29d0 [ 103.511769] ? avc_has_extended_perms+0x17f/0x440 [ 103.511820] ? tomoyo_init_request_info+0x84/0x90 [ 103.511870] ? tomoyo_path_number_perm+0x68/0x1e0 [ 103.511919] ? tty_insert_flip_string_fixed_flag+0x82/0xe0 [ 103.511973] ? inet_ioctl+0x187/0x1d0 [ 103.512016] dev_ioctl+0xb5/0x560 [ 103.512055] sock_do_ioctl+0xa0/0x140 [ 103.512098] sock_ioctl+0x2cb/0x3c0 [ 103.512139] __x64_sys_ioctl+0x84/0xc0 [ 103.512183] do_syscall_64+0x33/0x80 [ 103.512224] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 103.512274] RIP: 0033:0x7f54a9cba427 ...
Previous versions can be found at: v1: initial version https://lkml.org/lkml/2020/10/28/921
v2: do not return from lan743x_ethtool_set_wol if netdev->phydev == NULL, just skip the call of phy_ethtool_set_wol() instead. https://lkml.org/lkml/2020/10/31/380
v3: in function lan743x_ethtool_set_wol: use ternary operator instead of if-else sentence (review by Markus Elfring) return -ENETDOWN insted of -EIO (review by Andrew Lunn)
Signed-off-by: Sergej Bauer sbauer@blackbox.su
Link: https://lore.kernel.org/r/20201101223556.16116-1-sbauer@blackbox.su Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/microchip/lan743x_ethtool.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/microchip/lan743x_ethtool.c b/drivers/net/ethernet/microchip/lan743x_ethtool.c index dcde496da7fb4..c5de8f46cdd35 100644 --- a/drivers/net/ethernet/microchip/lan743x_ethtool.c +++ b/drivers/net/ethernet/microchip/lan743x_ethtool.c @@ -780,7 +780,9 @@ static void lan743x_ethtool_get_wol(struct net_device *netdev,
wol->supported = 0; wol->wolopts = 0; - phy_ethtool_get_wol(netdev->phydev, wol); + + if (netdev->phydev) + phy_ethtool_get_wol(netdev->phydev, wol);
wol->supported |= WAKE_BCAST | WAKE_UCAST | WAKE_MCAST | WAKE_MAGIC | WAKE_PHY | WAKE_ARP; @@ -809,9 +811,8 @@ static int lan743x_ethtool_set_wol(struct net_device *netdev,
device_set_wakeup_enable(&adapter->pdev->dev, (bool)wol->wolopts);
- phy_ethtool_set_wol(netdev->phydev, wol); - - return 0; + return netdev->phydev ? phy_ethtool_set_wol(netdev->phydev, wol) + : -ENETDOWN; } #endif /* CONFIG_PM */