A denial of service vulnerability was found in n_tty_receive_char_special in drivers/tty/n_tty.c of the Linux kernel. In this flaw a local attacker with a normal user privilege could delay the loop (due to a changing ldata->read_head, and a missing sanity check) and cause a threat to the system availability.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-20219
• https://bugzilla.redhat.com/show_bug.cgi?id=1923738