A potential stack overflow via infinite loop issue was found in various NIC emulators of QEMU in versions up to and including 5.2.0. The issue occurs in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A guest user/process may use this flaw to consume CPU cycles or crash the QEMU process on the host resulting in DoS scenario. There is a vulnerability in the lsi53c895a device which affects the latest version of qemu. The carefully designed PoC can repeatedly trigger DMA writes but does not limit the addresses written to the DMA, resulting in reentrancy issues and eventually overflow. 9pfs: prevent opening special files: A malicious client could potentially escape from the exported 9p tree by creating and opening a device file on host side