An issue was discovered in do_madvise in mm/madvise.c in the Linux kernel before 5.6.8. There is a race condition between coredump operations and the IORING_OP_MADVISE implementation, aka CID-bc0c4d1e176e.
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.6.8
https://bugs.chromium.org/p/project-zero/issues/detail?id=2029
http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html