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

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

bpf: Take mmap_lock in zap_pages()

zap_vma_range() requires the owning mm's mmap_lock to be held.

Taking mmap_read_lock under arena->lock would AB-BA against arena_vm_close() and arena_map_mmap(), both of which run with mmap_write_lock held and then acquire arena->lock. Instead drop arena->lock, mmget_not_zero() the vma's mm, take mmap_read_lock, and re-resolve the vma via find_vma() since it may have been unmapped or replaced while waiting.

Track processed vmls with a per-call generation in vml->zap_gen and serialize zap_pages() callers with a new arena->zap_mutex so concurrent callers on different uaddr ranges do not mark each other's vmls processed before the zap is done.

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

bpf: Take mmap_lock in zap_pages()

zap_vma_range() requires the owning mm's mmap_lock to be held.

Taking mmap_read_lock under arena->lock would AB-BA against arena_vm_close() and arena_map_mmap(), both of which run with mmap_write_lock held and then acquire arena->lock. Instead drop arena->lock, mmget_not_zero() the vma's mm, take mmap_read_lock, and re-resolve the vma via find_vma() since it may have been unmapped or replaced while waiting.

Track processed vmls with a per-call generation in vml->zap_gen and serialize zap_pages() callers with a new arena->zap_mutex so concurrent callers on different uaddr ranges do not mark each other's vmls processed before the zap is done.

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 120 more

In the Linux kernel, the following vulnerability has been resolved: bpf: Take mmap_lock in zap_pages() zap_vma_range() requires the owning mm's mmap_lock to be held. Taking mmap_read_lock under arena->lock would AB-BA against arena_vm_close() and arena_map_mmap(), both of which run with mmap_write_lock held and then acquire arena->lock. Instead drop arena->lock, mmget_not_zero() the vma's mm, take mmap_read_lock, and re-resolve the vma via find_vma() since it may have been unmapped or replaced while waiting. Track processed vmls with a per-call generation in vml->zap_gen and serialize zap_pages() callers with a new arena->zap_mutex so concurrent callers on different uaddr ranges do not mark each other's vmls processed before the zap is done.

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.