fs/namei.c in the Linux kernel before 5.5 has a may_create_in_sticky use-after-free, which allows local users to cause a denial of service (OOPS) or possibly obtain sensitive information from kernel memory, aka CID-d0cb50185ae9. One attack vector may be an open system call for a UNIX domain socket, if the socket is being moved to a new parent directory and its old parent directory is being removed. Reference: https://www.openwall.com/lists/oss-security/2020/02/02/1 https://www.openwall.com/lists/oss-security/2020/01/28/4 https://www.openwall.com/lists/oss-security/2020/01/28/2 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d0cb50185ae942b03c4327be322055d622dc79f6 https://github.com/torvalds/linux/commit/d0cb50185ae942b03c4327be322055d622dc79f6
CVE-2020-8647: https://nvd.nist.gov/vuln/detail/CVE-2020-8647 https://bugzilla.kernel.org/show_bug.cgi?id=206359 CVE-2020-8648: https://nvd.nist.gov/vuln/detail/CVE-2020-8648 https://bugzilla.kernel.org/show_bug.cgi?id=206361 CVE-2020-8649: https://nvd.nist.gov/vuln/detail/CVE-2020-8649 https://bugzilla.kernel.org/show_bug.cgi?id=206357
Fixes at the latest merged for 5.5.9 and all long backported to stable trees.
