Ubuntu Security Notice 4439-1 - It was discovered that the network block device implementation in the Linux kernel did not properly check for error conditions in some situations. An attacker could possibly use this to cause a denial of service. It was discovered that the btrfs file system implementation in the Linux kernel did not properly validate file system metadata in some situations. An attacker could use this to construct a malicious btrfs image that, when mounted, could cause a denial of service. Various other issues were also addressed.
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