net: mana: Guard mana_remove against double invocation

Overview

In the Linux kernel, the following vulnerability has been resolved:

net: mana: Guard mana_remove against double invocation

If PM resume fails (e.g., mana_attach() returns an error), mana_probe() calls mana_remove(), which tears down the device and sets gd->gdma_context = NULL and gd->driver_data = NULL.

However, a failed resume callback does not automatically unbind the driver. When the device is eventually unbound, mana_remove() is invoked a second time. Without a NULL check, it dereferences gc->dev with gc == NULL, causing a kernel panic.

Add an early return if gdma_context or driver_data is NULL so the second invocation is harmless. Move the dev = gc->dev assignment after the guard so it cannot dereference NULL.

Affected

• Linux >= 635096a86edb067d55a1e04b4a918f5c6dac0c51 < 793bf1f4e469c51d0e39199823da5e1de85a2741
• Linux >= 635096a86edb067d55a1e04b4a918f5c6dac0c51 < 8ee85b75a72216c857c39457f6595709c4c9f856
• Linux >= 635096a86edb067d55a1e04b4a918f5c6dac0c51 < a1ddfd2c0b7a48e5239fadd2a24cc4bc2cda90e6
• Linux >= 635096a86edb067d55a1e04b4a918f5c6dac0c51 < bbe5c3c570645a4ceb120979d3ee203a1583d775
• Linux >= 635096a86edb067d55a1e04b4a918f5c6dac0c51 < 50271d7ec95144d26808025b508f463780517d3c
• Linux 5.16

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.