An issue was discovered in the Linux kernel before 4.19.3. crypto_report_one() and related functions in crypto/crypto_user.c (the crypto user configuration API) do not fully initialize structures that are copied to userspace, potentially leaking sensitive memory to user programs. NOTE: this is a CVE-2013-2547 regression but with easier exploitability because the attacker does not need a capability (however, the system must have the CONFIG_CRYPTO_USER kconfig option).
https://usn.ubuntu.com/3901-2/
https://usn.ubuntu.com/3901-1/
https://usn.ubuntu.com/3878-2/
https://usn.ubuntu.com/3878-1/
https://usn.ubuntu.com/3872-1/
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.3
https://github.com/torvalds/linux/commit/f43f39958beb206b53292801e216d9b8a660f087
https://access.redhat.com/errata/RHSA-2019:3517