net/mlx5e: Fix null deref accessing lag dev

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix null deref accessing lag dev It could be the lag dev is null so stop processing the event. In bond_enslave() the active/backup slave being set before setting the upper dev so first event is without an upper dev. After setting the upper dev with bond_master_upper_dev_link() there is a second event and in that event we have an upper dev.

References

• https://git.kernel.org/stable/c/2e4b0b95a489259f9d35a3db17023061f8f3d587
• https://git.kernel.org/stable/c/bdfd3593a8248eea6ecfcbf7b47b56b86515672d
• https://git.kernel.org/stable/c/83026d83186bc48bb41ee4872f339b83f31dfc55