An issue was discovered in fs/nfs/dir.c in the Linux kernel before 5.16.5. If an application sets the O_DIRECTORY flag, and tries to open a regular file, nfs_atomic_open() performs a regular lookup. If a regular file is found, ENOTDIR should occur, but the server instead returns uninitialized data in the file descriptor.
https://www.spinics.net/lists/stable/msg531976.html
https://www.debian.org/security/2022/dsa-5096
https://www.debian.org/security/2022/dsa-5092
https://lore.kernel.org/all/67d6a536-9027-1928-99b6-af512a36cd1a%40huawei.com/T/
https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html
https://github.com/torvalds/linux/commit/ac795161c93699d600db16c1a8cc23a65a1eceaf
https://github.com/torvalds/linux/commit/ab0fc21bc7105b54bafd85bd8b82742f9e68898a
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.5