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

xfs: initialise args->total for parent pointer updates

xfs_parent_da_args_init() builds an xfs_da_args from a zeroed xfs_parent_args (kmem_cache_zalloc), leaving args->total == 0. xfs_da_grow_inode_int() treats that field as a running block reservation and subtracts from it; because it is an xfs_extlen_t (uint32_t), the first attr-fork growth wraps it to ~0U. That defeats the free-space check in xfs_alloc_space_available(), and when it coincides with an AG that has exactly zero available blocks the allocation is clamped to maxlen 0 and returns -ENOSPC, which xfs_defer_finish_noroll() escalates to a filesystem shutdown.

Set args->total the way the log recovery path does (xfs_attri_recover_work(), xfs_attr_item.c:706), in the add and replace paths that can grow the fork. Removals and lookups never grow it, so they leave the field alone, matching that switch.

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

xfs: initialise args->total for parent pointer updates

xfs_parent_da_args_init() builds an xfs_da_args from a zeroed xfs_parent_args (kmem_cache_zalloc), leaving args->total == 0. xfs_da_grow_inode_int() treats that field as a running block reservation and subtracts from it; because it is an xfs_extlen_t (uint32_t), the first attr-fork growth wraps it to ~0U. That defeats the free-space check in xfs_alloc_space_available(), and when it coincides with an AG that has exactly zero available blocks the allocation is clamped to maxlen 0 and returns -ENOSPC, which xfs_defer_finish_noroll() escalates to a filesystem shutdown.

Set args->total the way the log recovery path does (xfs_attri_recover_work(), xfs_attr_item.c:706), in the add and replace paths that can grow the fork. Removals and lookups never grow it, so they leave the field alone, matching that switch.

Affected: Ubuntu:Pro:14.04:LTS: linux, 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 and 246 more

In the Linux kernel, the following vulnerability has been resolved: xfs: initialise args->total for parent pointer updates xfs_parent_da_args_init() builds an xfs_da_args from a zeroed xfs_parent_args (kmem_cache_zalloc), leaving args->total == 0. xfs_da_grow_inode_int() treats that field as a running block reservation and subtracts from it; because it is an xfs_extlen_t (uint32_t), the first attr-fork growth wraps it to ~0U. That defeats the free-space check in xfs_alloc_space_available(), and when it coincides with an AG that has exactly zero available blocks the allocation is clamped to maxlen 0 and returns -ENOSPC, which xfs_defer_finish_noroll() escalates to a filesystem shutdown. Set args->total the way the log recovery path does (xfs_attri_recover_work(), xfs_attr_item.c:706), in the add and replace paths that can grow the fork. Removals and lookups never grow it, so they leave the field alone, matching that switch.

Ein lokaler Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Zustand herbeizuführen oder nicht näher spezifizierten Angriff durchzuführen.