CVE-2026-22991: NULL Pointer Dereference

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

libceph: make free_choose_arg_map() resilient to partial allocation

free_choose_arg_map() may dereference a NULL pointer if its caller fails after a partial allocation.

For example, in decode_choose_args(), if allocation of arg_map->args fails, execution jumps to the fail label and free_choose_arg_map() is called. Since arg_map->size is updated to a non-zero value before memory allocation, free_choose_arg_map() will iterate over arg_map->args and dereference a NULL pointer.

To prevent this potential NULL pointer dereference and make free_choose_arg_map() more resilient, add checks for pointers before iterating.