kernel is vulnerable to use-after-free. drivers/tty/tty_jobctrl.c allows a use-after-free attack against TIOCSPGRP, aka CID-54ffccbf053b. A locking vulnerability was found in the tty subsystem of the Linux kernel in drivers/tty/tty_jobctrl.c. This flaw allows a local attacker to possibly corrupt memory or escalate privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
packetstormsecurity.com/files/160681/Linux-TIOCSPGRP-Broken-Locking.html
packetstormsecurity.com/files/164950/Kernel-Live-Patch-Security-Notice-LSN-0082-1.html
www.openwall.com/lists/oss-security/2020/12/10/1
access.redhat.com/errata/RHSA-2021:0558
access.redhat.com/security/updates/classification/#important
bugzilla.redhat.com/show_bug.cgi?id=1906525
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=54ffccbf053b5b6ca4f6e45094b942fab92a25fc
lists.debian.org/debian-lts-announce/2021/02/msg00018.html
lists.debian.org/debian-lts-announce/2021/03/msg00010.html
lists.fedoraproject.org/archives/list/[email protected]/message/BOB25SU6XUL4TNP7KB63WNZSYTIYFDPP/
lists.fedoraproject.org/archives/list/[email protected]/message/MZ7OAKAEFAXQRGBZK4LYUWINCD3D2XCL/
security.netapp.com/advisory/ntap-20210122-0001/
www.debian.org/security/2021/dsa-4843
www.oracle.com/security-alerts/cpuoct2021.html