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

tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper()

tee_dyn_shm_alloc_helper() derives nr_pages from a caller-supplied size and passes it to alloc_pages_exact() without checking it. For size == 0 nr_pages is 0, and alloc_pages_exact(0) calls get_order(0), which is documented as undefined and returns BITS_PER_LONG - PAGE_SHIFT. The page allocator then trips its order > MAX_PAGE_ORDER warning and fails the allocation; on a panic_on_warn kernel that ends the boot.

This can be triggered by TEE_IOC_SHM_ALLOC with struct tee_ioctl_shm_alloc_data where size is 0.

Reject a zero page count, as register_shm_helper() already does for the register path.

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

tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper()

tee_dyn_shm_alloc_helper() derives nr_pages from a caller-supplied size and passes it to alloc_pages_exact() without checking it. For size == 0 nr_pages is 0, and alloc_pages_exact(0) calls get_order(0), which is documented as undefined and returns BITS_PER_LONG - PAGE_SHIFT. The page allocator then trips its order > MAX_PAGE_ORDER warning and fails the allocation; on a panic_on_warn kernel that ends the boot.

This can be triggered by TEE_IOC_SHM_ALLOC with struct tee_ioctl_shm_alloc_data where size is 0.

Reject a zero page count, as register_shm_helper() already does for the register path.

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 129 more

In the Linux kernel, the following vulnerability has been resolved: tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper() tee_dyn_shm_alloc_helper() derives nr_pages from a caller-supplied size and passes it to alloc_pages_exact() without checking it. For size == 0 nr_pages is 0, and alloc_pages_exact(0) calls get_order(0), which is documented as undefined and returns BITS_PER_LONG - PAGE_SHIFT. The page allocator then trips its order > MAX_PAGE_ORDER warning and fails the allocation; on a panic_on_warn kernel that ends the boot. This can be triggered by TEE_IOC_SHM_ALLOC with struct tee_ioctl_shm_alloc_data where size is 0. Reject a zero page count, as register_shm_helper() already does for the register path.