Existing timing attacks on garbage collectors from Google Scholar:

<http://www.ieee-security.org/TC/SP2017/papers/258.pdf>
 From trash to treasure: timing-sensitive garbage collection (2017)

Abstract: "This   paper   studies   information   flows   via
timingchannels in the presence of automatic memory management.
Weconstruct a series of example attacks that illustrate that
garbagecollectors  form  a  shared  resource  that  can  be  used  to
reliablyleak  sensitive  information  at  a  rate  of  up  to  1
byte/sec  on  acontemporary general-purpose computer. The created
channel isalso observable across a network connection in a
datacenter-likesetting. We  subsequently present  a design  of
automatic  memorymanagement  that  is  provably  resilient  against
such  attacks."

Eliminating Cache-Based Timing Attacks with Instruction-Based Scheduling
(2013)
<http://amitlevy.com/papers/eliminating-esorics2013.pdf>

Excerpt from the paper: "Though GHC already inserts many safe points as
a meansof invoking the garbage collector (via the scheduler), tight
loops that do not perform anyallocation are known to hang execution [1].
Addressing this eight-year old bug, whichwould otherwise be a security
concern in LIO, we modified the compiler to insert safepoints on
function entry points. This modification, integrated in the mainline
GHC, hasalmost no effect on performance and only a 7% bloat in average
binary size."