In the Linux kernel 4.19.83, there is a use-after-free (read) in the debugfs_remove function in fs/debugfs/inode.c (which is used to remove a file or directory in debugfs that was previously created with a call to another debugfs function such as debugfs_create_file).

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-19770
• https://bugzilla.kernel.org/show_bug.cgi?id=205713
• https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
• http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00035.html
• https://lore.kernel.org/linux-block/20200402000002.7442-1-mcgrof%40kernel.org
• https://lore.kernel.org/linux-block/20200402000002.7442-1-mcgrof@kernel.org
• https://security.netapp.com/advisory/ntap-20200103-0001