In the Linux kernel, the following vulnerability has been resolved:
dpll: fix xaalloccyclic() error handling
In case of returning 1 from xaalloccyclic() (wrapping) ERRPTR(1) will be returned, which will cause ISERR() to be false. Which can lead to dereference not allocated pointer (pin).
Fix it by checking if err is lower than zero.
This wasn't found in real usecase, only noticed. Credit to Pierre.