USN-3718-1

USN-3695-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. Unfortunately, the fix for CVE-2018-1108 introduced a regression where insufficient early entropy prevented services from starting, leading in some situations to a failure to boot, This update addresses the issue.

We apologize for the inconvenience.

Original advisory details:

Jann Horn discovered that the Linux kernel's implementation of random seed data reported that it was in a ready state before it had gathered sufficient entropy. An attacker could use this to expose sensitive information. (CVE-2018-1108)

Wen Xu discovered that the ext4 file system implementation in the Linux kernel did not properly initialize the crc32c checksum driver. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1094)

It was discovered that the cdrom driver in the Linux kernel contained an incorrect bounds check. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-10940)

Wen Xu discovered that the ext4 file system implementation in the Linux kernel did not properly validate xattr sizes. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1095)

Jann Horn discovered that the 32 bit adjtimex() syscall implementation for 64 bit Linux kernels did not properly initialize memory returned to user space in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-11508)

It was discovered that an information leak vulnerability existed in the floppy driver in the Linux kernel. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-7755)