Arch Linux

Description:
Kernel keyring bug allows unprivileged user to exhaust kernel memory.

Additional info:
Fix is stable queue so should be fixed in stable releases 4.10.13 and 4.9.25

https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-4.10/keys-fix-keyctl_set_reqkey_keyring-to-not-leak-thread-keyrings.patch
https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-4.9/keys-fix-keyctl_set_reqkey_keyring-to-not-leak-thread-keyrings.patch

Steps to reproduce:
Running the following program as an unprivileged user exhausts kernel
memory by leaking thread keyrings:

#include <keyutils.h>
int main()
{
for (;;)
keyctl_set_reqkey_keyring(KEY_REQKEY_DEFL_THREAD_KEYRING);
}

If you are going to patch this before the above stable releases please consider also applying the other two key related patches that also have CVE's but seem more minor
4.10
CVE-2017-6951 https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-4.10/keys-change-the-name-of-the-dead-type-to-.dead-to-prevent-user-access.patch
CVE-2016-9604 https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-4.10/keys-disallow-keyrings-beginning-with-.-to-be-joined-as-session-keyrings.patch
4.9
CVE-2017-6951 https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-4.9/keys-change-the-name-of-the-dead-type-to-.dead-to-prevent-user-access.patch
CVE-2016-9604 https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-4.9/keys-disallow-keyrings-beginning-with-.-to-be-joined-as-session-keyrings.patch