Commit e0ad2cd8 authored by Anton Vorontsov's avatar Anton Vorontsov Committed by David S. Miller

ucc_geth: Fix NULL pointer dereference in uec_get_ethtool_stats()

In commit 3e73fc9a ("ucc_geth: Fix IO
memory (un)mapping code") I fixed ug_regs IO memory leak by properly
freeing the allocated memory. But ethtool_stats() callback doesn't
check for ug_regs being NULL, and that causes following oops if
'ethtool -S' is executed on a closed eth device:

  Unable to handle kernel paging request for data at address 0x00000180
  Faulting instruction address: 0xc0208228
  Oops: Kernel access of bad area, sig: 11 [#1]
  ...
  NIP [c0208228] uec_get_ethtool_stats+0x38/0x140
  LR [c02559a0] ethtool_get_stats+0xf8/0x23c
  Call Trace:
  [ef87bcd0] [c025597c] ethtool_get_stats+0xd4/0x23c (unreliable)
  [ef87bd00] [c025706c] dev_ethtool+0xfe8/0x11bc
  [ef87be00] [c0252b5c] dev_ioctl+0x454/0x6a8
  ...
  ---[ end trace 77fff1162a9586b0 ]---
  Segmentation fault

This patch fixes the issue.
Signed-off-by: default avatarAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b9caaabb
......@@ -319,9 +319,13 @@ static void uec_get_ethtool_stats(struct net_device *netdev,
int i, j = 0;
if (stats_mode & UCC_GETH_STATISTICS_GATHERING_MODE_HARDWARE) {
base = (u32 __iomem *)&ugeth->ug_regs->tx64;
if (ugeth->ug_regs)
base = (u32 __iomem *)&ugeth->ug_regs->tx64;
else
base = NULL;
for (i = 0; i < UEC_HW_STATS_LEN; i++)
data[j++] = in_be32(&base[i]);
data[j++] = base ? in_be32(&base[i]) : 0;
}
if (stats_mode & UCC_GETH_STATISTICS_GATHERING_MODE_FIRMWARE_TX) {
base = (u32 __iomem *)ugeth->p_tx_fw_statistics_pram;
......
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