In the Linux kernel, the following vulnerability has been resolved: tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper()

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.