Description

In the Linux kernel, the following vulnerability has been resolved: power: supply: wm97xx: Fix NULL pointer dereference in power_supply_changed() In `probe()`, `request_irq()` is called before allocating/registering a `power_supply` handle. If an interrupt is fired between the call to `request_irq()` and `power_supply_register()`, the `power_supply` handle will be used uninitialized in `power_supply_changed()` in `wm97xx_bat_update()` (triggered from the interrupt handler). This will lead to a `NULL` pointer dereference since Fix this racy `NULL` pointer dereference by making sure the IRQ is requested _after_ the registration of the `power_supply` handle. Since the IRQ is the last thing requests in the `probe()` now, remove the error path for freeing it. Instead add one for unregistering the `power_supply` handle when IRQ request fails.

References 8

• git.kernel.org https://git.kernel.org/stable/c/39fe0eac6d755ef215026518985fcf8de9360e9e
• git.kernel.org https://git.kernel.org/stable/c/3d7b5391bb95505b3581c1fb77150c467ab92864
• git.kernel.org https://git.kernel.org/stable/c/438f9a303ea8b55162b2d5376490c2ab3ec165a0
• git.kernel.org https://git.kernel.org/stable/c/86183153c299e8bb1839e717286d6c6f39508a59
• git.kernel.org https://git.kernel.org/stable/c/93bdf715d33cf5ee01c58e8546c2469c71ce082a
• git.kernel.org https://git.kernel.org/stable/c/9b7d77cb046b4487e8e511e04e62b6f416ce845c
• git.kernel.org https://git.kernel.org/stable/c/c0def811ad8d642dca9b6d31a198cc39f5f90837
• git.kernel.org https://git.kernel.org/stable/c/dfaf235d5a6b60cbf115a14a656946303ad007b7

Remediation