CVE-2024-26784

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

pmdomain: arm: Fix NULL dereference on scmiperfdomain removal

On unloading of the scmiperfdomain module got the below splat, when in the DT provided to the system under test the '#power-domain-cells' property was missing. Indeed, this particular setup causes the probe to bail out early without giving any error, which leads to the ->remove() callback gets to run too, but without all the expected initialized structures in place.

Add a check and bail out early on remove too.

Call trace: scmiperfdomainremove+0x28/0x70 [scmiperfdomain] scmidevremove+0x28/0x40 [scmicore] deviceremove+0x54/0x90 devicereleasedriverinternal+0x1dc/0x240 driverdetach+0x58/0xa8 busremovedriver+0x78/0x108 driverunregister+0x38/0x70 scmidriverunregister+0x28/0x180 [scmicore] scmiperfdomaindriverexit+0x18/0xb78 [scmiperfdomain] _arm64sysdeletemodule+0x1a8/0x2c0 invokesyscall+0x50/0x128 el0svccommon.constprop.0+0x48/0xf0 doel0svc+0x24/0x38 el0svc+0x34/0xb8 el0t64synchandler+0x100/0x130 el0t64sync+0x190/0x198 Code: a90153f3 f9403c14 f9414800 955f8a05 (b9400a80) ---[ end trace 0000000000000000 ]---