> -----Original Message-----
> From: Linkui Xiao <[email protected]>
> Sent: Wednesday, September 16, 2026 3:28 PM
> To: Nguyen, Anthony L <[email protected]>; Kitszel,
> Przemyslaw <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]
> Cc: [email protected]; [email protected]; linux-
> [email protected]; Linkui Xiao <[email protected]>;
> [email protected]
> Subject: [Intel-wired-lan] [PATCH net] igb: unregister the i2c adapter
> when register_netdev() fails
>
> From: Linkui Xiao <[email protected]>
>
> igb_probe() sets up the bit-banging i2c adapter with igb_init_i2c()
> before it registers the netdev, but the err_register path only zeroes
> adapter->i2c_adap instead of unregistering the adapter. On i350 parts,
> where igb_init_i2c() really registers the bus, the adapter is
> therefore still registered when free_netdev() releases the memory that
> embeds it.
> The i2c core keeps pointing at the freed adapter, so any later access
> to that bus dereferences freed memory, and the adapter number is
> leaked.
>
> Call igb_remove_i2c() instead, the same way igb_remove() tears the bus
> down. Move the helper next to igb_init_i2c() so that it is in scope
> for igb_probe(). i2c_del_adapter() returns early for an adapter that
> was never registered, so the parts without i2c support are unaffected.
>
> Fixes: 441fc6fdb47a ("igb: Add i2c interface to igb.")
> Cc: [email protected]
> Signed-off-by: Linkui Xiao <[email protected]>
> ---
> drivers/net/ethernet/intel/igb/igb_main.c | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
> b/drivers/net/ethernet/intel/igb/igb_main.c
> index d4a897a8c82c..f965ca144f42 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -3190,6 +3190,16 @@ static s32 igb_init_i2c(struct igb_adapter
> *adapter)
> return status;
> }
>
> +/**
> + * igb_remove_i2c - Cleanup I2C interface
> + * @adapter: pointer to adapter structure **/ static void
> +igb_remove_i2c(struct igb_adapter *adapter) {
> + /* free the adapter bus structure */
> + i2c_del_adapter(&adapter->i2c_adap);
> +}
> +
> /**
> * igb_probe - Device Initialization Routine
> * @pdev: PCI device information struct @@ -3657,7 +3667,7 @@ static
> int igb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>
> err_register:
> igb_release_hw_control(adapter);
> - memset(&adapter->i2c_adap, 0, sizeof(adapter->i2c_adap));
> + igb_remove_i2c(adapter);
> err_eeprom:
> if (!igb_check_reset_block(hw))
> igb_reset_phy(hw);
> @@ -3849,16 +3859,6 @@ static int igb_enable_sriov(struct pci_dev
> *pdev, int num_vfs, bool reinit) }
>
> #endif
> -/**
> - * igb_remove_i2c - Cleanup I2C interface
> - * @adapter: pointer to adapter structure
> - **/
> -static void igb_remove_i2c(struct igb_adapter *adapter) -{
> - /* free the adapter bus structure */
> - i2c_del_adapter(&adapter->i2c_adap);
> -}
> -
> /**
> * igb_remove - Device Removal Routine
> * @pdev: PCI device information struct
> --
> 2.25.1
Reviewed-by: Aleksandr Loktionov <[email protected]>
