Ubuntu Security Notice 3776-1 - Jann Horn discovered that the vmacache subsystem did not properly handle sequence number overflows, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service or execute arbitrary code. It was discovered that the paravirtualization implementation in the Linux kernel did not properly handle some indirect calls, reducing the effectiveness of Spectre v2 mitigations for paravirtual guests. A local attacker could use this to expose sensitive information. Various other issues were also addressed. Continue reading...
