net: phy: dp83822: Fix null pointer access on DP83825/DP83826 devices

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: net: phy: dp83822: Fix null pointer access on DP83825/DP83826 devices The probe() function is only used for the DP83822 PHY, leaving the private data pointer uninitialized for the smaller DP83825/26 models. While all uses of the private data structure are hidden in 82822 specific callbacks, configuring the interrupt is shared across all models. This causes a NULL pointer dereference on the smaller PHYs as it accesses the private data unchecked. Verifying the pointer avoids that.

References

• https://git.kernel.org/stable/c/362a2f5531dc0e5b0b5b3e3a541000dbffa75461
• https://git.kernel.org/stable/c/2cd1e9c013ec56421c58921b1ddf1d2d53bd47fa
• https://git.kernel.org/stable/c/78901b10522cdf6badf24acf65a892637596bccc
• https://git.kernel.org/stable/c/422ae7d9c7221e8d4c8526d0f54106307d69d2dc