When e1000_probe() fails, the shared error handling ladder attempts to
iounmap() the hw->ce4100_gbe_mdio_base_virt pointer. If the hardware is
not a CE4100, this pointer remains uninitialized (NULL). On architectures
like x86, passing a NULL pointer to iounmap() triggers a WARN_ON_ONCE,
which is fatal under panic_on_warn.

Fix this by conditionally unmapping the CE4100 MDIO base only if the
mac_type is e1000_ce4100, matching the exact logic used in e1000_remove().
The hw->hw_addr iounmap() remains unconditional since it is guaranteed to
be valid for all error paths reaching the err_sw_init label.

Reported-by: syzbot+ca1ef9e2e234b8d3599b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ca1ef9e2e234b8d3599b
Fixes: 13acde8fffc0af ("e1000: Fix the CE4100 bus type for the MDIO/PHY registers")
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Svyatoslav Nikolenko <nsvatoslav515@gmail.com>
---
v3:
  - Switched from pointer null-checks to checking hw->mac_type == e1000_ce4100
  - Removed redundant check for hw->hw_addr since it cannot be NULL here
  - Added missing Cc: stable tag and Closes tag
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

Please drop this version. I accidentally sent this without staging my
local changes.
Sending v4 shortly with the actual code.


чт, 24 вер. 2026 р. о 12:52 Svyatoslav Nikolenko <nsvatoslav515@gmail.com> пише:
>
> When e1000_probe() fails, the shared error handling ladder attempts to
> iounmap() the hw->ce4100_gbe_mdio_base_virt pointer. If the hardware is
> not a CE4100, this pointer remains uninitialized (NULL). On architectures
> like x86, passing a NULL pointer to iounmap() triggers a WARN_ON_ONCE,
> which is fatal under panic_on_warn.
>
> Fix this by conditionally unmapping the CE4100 MDIO base only if the
> mac_type is e1000_ce4100, matching the exact logic used in e1000_remove().
> The hw->hw_addr iounmap() remains unconditional since it is guaranteed to
> be valid for all error paths reaching the err_sw_init label.
>
> Reported-by: syzbot+ca1ef9e2e234b8d3599b@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=ca1ef9e2e234b8d3599b
> Fixes: 13acde8fffc0af ("e1000: Fix the CE4100 bus type for the MDIO/PHY registers")
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Svyatoslav Nikolenko <nsvatoslav515@gmail.com>
> ---
> v3:
>   - Switched from pointer null-checks to checking hw->mac_type == e1000_ce4100
>   - Removed redundant check for hw->hw_addr since it cannot be NULL here
>   - Added missing Cc: stable tag and Closes tag
> 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
>