kernel/omap/drivers/rpmsg/rpmsg_omx.c in the kernel component in Amazon Kindle Fire HD(3rd) Fire OS 4.5.5.3 allows attackers to inject a crafted argument via the argument of an ioctl on device file /dev/rpmsg-omx1 with the command 3221772291, and cause a kernel crash.
Stack-based buffer overflow in the havok_write function in drivers/staging/havok/havok.c in Amazon Fire OS before 2016-01-15 allows attackers to cause a denial of service (panic) or possibly have unspecified other impact via a long string to /dev/hv.