In e1000_probe(), the error unwinding path at err_sw_init unconditionally calls iounmap(hw->ce4100_gbe_mdio_base_virt). On non-CE4100 hardware, hw->ce4100_gbe_mdio_base_virt remains NULL. Passing NULL to iounmap() triggers a WARN_ON_ONCE on x86 architectures. Furthermore, on CE4100 hardware, if probe fails before or during MDIO mapping, ce4100_gbe_mdio_base_virt is also NULL.
Fix this by adding a NULL pointer check before calling iounmap() on hw->ce4100_gbe_mdio_base_virt. iounmap(hw->hw_addr) remains unconditional because every code path reaching err_sw_init occurs after hw->hw_addr has been successfully mapped. Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=ca1ef9e2e234b8d3599b Fixes: 13acde8fffc0 ("e1000: cleanup CE4100 MDIO registers access") Cc: [email protected] Signed-off-by: Svyatoslav Nikolenko <[email protected]> --- v5: - Updated commit message and changelog to accurately describe the NULL pointer check implemented in the diff. - Fixed subject string in the Fixes: tag to match commit 13acde8fffc0. v4: - Actually include the code changes (v3 was sent un-staged by mistake) 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 drivers/net/ethernet/intel/e1000/e1000_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index d7f5c6f16142..d7e279b739b8 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -1227,7 +1227,8 @@ 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); + if (hw->ce4100_gbe_mdio_base_virt) + iounmap(hw->ce4100_gbe_mdio_base_virt); iounmap(hw->hw_addr); err_ioremap: disable_dev = !test_and_set_bit(__E1000_DISABLED, &adapter->flags); -- 2.47.3
