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

of/overlay: don't leak fragment references when changeset init fails

init_overlay_changeset() stores the number of initialized fragments in ovcs->count only on full success. When find_target() or the __symbols__ lookup fails partway through, the target and overlay references taken for the fragments initialized so far are never dropped: free_overlay_changeset() bounds its cleanup loop by ovcs->count, which is still 0.

Store the running count on the error path so free_overlay_changeset() puts whatever was set up. The store is guarded by ovcs->fragments because on the allocation-failure path cnt still holds the counting pass total while there is no fragments array; everywhere else cnt only counts fully-initialized fragments.

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

of/overlay: don't leak fragment references when changeset init fails

init_overlay_changeset() stores the number of initialized fragments in ovcs->count only on full success. When find_target() or the __symbols__ lookup fails partway through, the target and overlay references taken for the fragments initialized so far are never dropped: free_overlay_changeset() bounds its cleanup loop by ovcs->count, which is still 0.

Store the running count on the error path so free_overlay_changeset() puts whatever was set up. The store is guarded by ovcs->fragments because on the allocation-failure path cnt still holds the counting pass total while there is no fragments array; everywhere else cnt only counts fully-initialized fragments.

Affected: Ubuntu:Pro:14.04:LTS: linux-azure, 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, Ubuntu:Pro:16.04:LTS: linux-oracle, Ubuntu:Pro:18.04:LTS: linux, Ubuntu:Pro:18.04:LTS: linux-aws, Ubuntu:18.04:LTS: linux-aws-5.0 and 239 more

In the Linux kernel, the following vulnerability has been resolved: of/overlay: don't leak fragment references when changeset init fails init_overlay_changeset() stores the number of initialized fragments in ovcs->count only on full success. When find_target() or the __symbols__ lookup fails partway through, the target and overlay references taken for the fragments initialized so far are never dropped: free_overlay_changeset() bounds its cleanup loop by ovcs->count, which is still 0. Store the running count on the error path so free_overlay_changeset() puts whatever was set up. The store is guarded by ovcs->fragments because on the allocation-failure path cnt still holds the counting pass total while there is no fragments array; everywhere else cnt only counts fully-initialized fragments.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, möglicherweise einen Denial-of-Service-Angriff auszulösen, Daten zu manipulieren oder offenzulegen oder Sicherheitsmaßnahmen zu umgehen.