In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix preempt count leak in napi poll tracepoint
Using get_cpu() in the tracepoint assignment causes an obvious preempt
count leak because nothing invokes put_cpu() to undo it:
softirq: huh, entered softirq 3 NET_RX with preempt_count 00000100, exited with 00000101?
This clearly has seen a lot of testing in the last 3+ years...
Use smp_processor_id() instead.
References 4
https://git.kernel.org/stable/c/4b3d54a85bd37ebf2d9836f0d0de775c0ff21af9
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9e0f091821571f0da387462803ee42f0bb157582
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b7e91827e1cf89cd34ad11dc8f8c010b70ab786e
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/dca4ea596a3b0a1b82bc1d9f3e4d88bd9ad9561f
416baaa9-dc9f-4396-8d5f-8c081fb06d67