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. Fixes: cf4441503e20 ("tee: optee: Move pool_op helper functions") Cc: stable@vger.kernel.org Cc: lvc-project@linuxtesting.org Signed-off-by: Georgiy Osokin --- drivers/tee/tee_shm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 6742b3579..daa4af1e0 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -343,6 +343,10 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align, unsigned int i; int rc = 0; + /* get_order(0) is undefined and exceeds MAX_PAGE_ORDER. */ + if (!nr_pages) + return -EINVAL; + /* * Ignore alignment since this is already going to be page aligned * and there's no need for any larger alignment. base-commit: 72d3fcf802c45d00b300f25b848a93c3a2bd7c7e -- 2.54.0