[LU-15615] memory leak on use_t10_grd path in tgt_checksum_niobuf_t10pi

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Severity: 3
• Assignee: Oleg Drokin
• Reporter: Oleg Drokin

Description

It looks like tgt_checksum_niobuf_t10pi() can leak memory if we ever set rc to nonzero, some of the conditions appear to set it without any visible warnings:

        req = cfs_crypto_hash_init(cfs_alg, NULL, 0);
        if (IS_ERR(req)) {
                CERROR("%s: unable to initialize checksum hash %s\n",
                       tgt_name(tgt), cfs_crypto_hash_name(cfs_alg));
                return PTR_ERR(req);
        }
...
                if (use_t10_grd) {
                        used = DIV_ROUND_UP(local_nb[i].lnb_len, sector_size);
                        if (used > (guard_number - used_number)) {
                                rc = -E2BIG;
                                break;
                        }
...
        if (rc)
                GOTO(out, rc);
...
        rc = cfs_crypto_hash_final(req, (unsigned char *)&cksum, &bufsize);
        if (rc == 0)
                *check_sum = cksum;
out:
        __free_page(__page);
        return rc;
}

This not only leads to leaking the req, but also the allocated page might be tied in the crypto hash calcs I imagine (passed in as sg buffer with a reference to be potentially freed in the final?)

Issue Links

• is duplicated by: LU-15500 Crash in crypto_unregister_alg on client modules unload
• is related to: LU-15598 page leak on cfs_crypto_hash_init() error path in tgt_checksum_niobuf_t10pi