[LU-15013] potential null pointer access in osc_prep_async_page

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.15.0
• Affects Version/s: Lustre 2.15.0
• Severity: 3
• Assignee: James A Simmons
• Reporter: Oleg Drokin

Description

Introduced by https://review.whamcloud.com/44338

 

        while (--max_scans > 0 &&
               (cli = list_first_entry_or_null(&cache->ccc_lru,
                                               struct client_obd,
                                               cl_lru_osc)) != NULL) {
...
                }
        }
        spin_unlock(&cache->ccc_lru_lock);out:
        cl_env_put(env, &refcheck);
        CDEBUG(D_CACHE, "%s: cli %p freed %ld pages.\n",
                cli_name(cli), cli, rc); 

So now once that cli is NULL we exit and cli_name dereference will get us if +cache is in the debug flags.