During a probe failure, the e1000 driver error handling path calls
iounmap() on hw->ce4100_gbe_mdio_base_virt and hw->hw_addr without
checking if they were previously mapped. This triggers a kernel warning
(WARN) rather than a fatal crash when passed an uninitialized pointer.
This issue was found by Syzbot. The exact kernel configuration (.config)
and the C reproducer used to trigger this warning are available on the
Syzbot dashboard.
Fix this by adding NULL checks before calling iounmap().
Reported-by: syzbot+ca1ef9e2e234b8d3599b@syzkaller.appspotmail.com
Fixes: 13acde8fffc0a ("e1000: cleanup CE4100 MDIO registers access")
Fixes: 1dc329180fe22 ("e1000: Use hw, er32, and ew32")
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Svyatoslav Nikolenko <nsvatoslav515@gmail.com>
---
v2:
- Expanded commit message to answer reviewer questions (reproduction details)
- Added appropriate Fixes tags
- Added Reviewed-by tag from Aleksandr Loktionov
drivers/net/ethernet/intel/e1000/e1000_main.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index d7f5c6f16142..156903089fa6 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -1227,8 +1227,10 @@ static int e1000_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
kfree(adapter->rx_ring);
err_dma:
err_sw_init:
- iounmap(hw->ce4100_gbe_mdio_base_virt);
- iounmap(hw->hw_addr);
+ if (hw->ce4100_gbe_mdio_base_virt)
+ iounmap(hw->ce4100_gbe_mdio_base_virt);
+ if (hw->hw_addr)
+ iounmap(hw->hw_addr);
err_ioremap:
disable_dev = !test_and_set_bit(__E1000_DISABLED, &adapter->flags);
free_netdev(netdev);
--
2.47.3