Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: reject FITRIM ranges shorter than a cluster

ocfs2_trim_mainbm() trims the global bitmap in cluster units, but its too-short range validation only checks sb->s_blocksize.

On filesystems with a cluster size larger than the block size, a FITRIM range that is at least one block but shorter than one cluster is accepted and shifted down to len == 0. The later start + len - 1 and len -= ... arithmetic then underflows and can drive trimming past the requested range.

Reject ranges shorter than s_clustersize instead. That preserves the existing -EINVAL behavior for requests that cannot discard even one allocation unit and keeps zero-cluster trims out of the group walk.

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: reject FITRIM ranges shorter than a cluster

ocfs2_trim_mainbm() trims the global bitmap in cluster units, but its too-short range validation only checks sb->s_blocksize.

On filesystems with a cluster size larger than the block size, a FITRIM range that is at least one block but shorter than one cluster is accepted and shifted down to len == 0. The later start + len - 1 and len -= ... arithmetic then underflows and can drive trimming past the requested range.

Reject ranges shorter than s_clustersize instead. That preserves the existing -EINVAL behavior for requests that cannot discard even one allocation unit and keeps zero-cluster trims out of the group walk.

Security update for the Linux Kernel

Security update for the Linux Kernel

Affected: Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe, Ubuntu:16.04:LTS: linux-hwe-edge and 245 more

In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject FITRIM ranges shorter than a cluster ocfs2_trim_mainbm() trims the global bitmap in cluster units, but its too-short range validation only checks sb->s_blocksize. On filesystems with a cluster size larger than the block size, a FITRIM range that is at least one block but shorter than one cluster is accepted and shifted down to len == 0. The later start + len - 1 and len -= ... arithmetic then underflows and can drive trimming past the requested range. Reject ranges shorter than s_clustersize instead. That preserves the existing -EINVAL behavior for requests that cannot discard even one allocation unit and keeps zero-cluster trims out of the group walk.

Ein Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um root Rechte zu erlangen, um einen Denial of Service herbeizuführen oder einen nicht näher spezifizierten Angriff durchzuführen.