Hello Ondrej Mosnacek,
Commit c3a276111ea2 ("selinux: optimize storage of filename
transitions") from Feb 18, 2020 (linux-next), leads to the following
Smatch static checker warning:
security/selinux/ss/policydb.c:1953 filename_trans_read_helper_compat()
warn: missing error code 'rc'
security/selinux/ss/policydb.c
1916 static int filename_trans_read_helper_compat(struct policydb *p, void *fp)
1917 {
1918 struct filename_trans_key key, *ft = NULL;
1919 struct filename_trans_datum *last, *datum = NULL;
1920 char *name = NULL;
1921 u32 len, stype, otype;
1922 __le32 buf[4];
1923 int rc;
1924
1925 /* length of the path component string */
1926 rc = next_entry(buf, fp, sizeof(u32));
1927 if (rc)
1928 return rc;
1929 len = le32_to_cpu(buf[0]);
1930
1931 /* path component string */
1932 rc = str_read(&name, GFP_KERNEL, fp, len);
1933 if (rc)
1934 return rc;
1935
1936 rc = next_entry(buf, fp, sizeof(u32) * 4);
1937 if (rc)
1938 goto out;
1939
1940 stype = le32_to_cpu(buf[0]);
1941 key.ttype = le32_to_cpu(buf[1]);
1942 key.tclass = le32_to_cpu(buf[2]);
1943 key.name = name;
1944
1945 otype = le32_to_cpu(buf[3]);
1946
1947 last = NULL;
1948 datum = policydb_filenametr_search(p, &key);
1949 while (datum) {
1950 if (unlikely(ebitmap_get_bit(&datum->stypes, stype - 1))) {
1951 /* conflicting/duplicate rules are ignored */
1952 datum = NULL;
--> 1953 goto out;
It's not clear just from looking at this, if it should return zero or an
error code. The way to silence these warnings in smatch is to add a
"rc = 0;" within 5 lines of the goto. Or a comment would also help
reviewers.
1954 }
1955 if (likely(datum->otype == otype))
1956 break;
1957 last = datum;
1958 datum = datum->next;
1959 }
1960 if (!datum) {
1961 rc = -ENOMEM;
1962 datum = kmalloc(sizeof(*datum), GFP_KERNEL);
1963 if (!datum)
1964 goto out;
1965
1966 ebitmap_init(&datum->stypes);
1967 datum->otype = otype;
1968 datum->next = NULL;
1969
1970 if (unlikely(last)) {
1971 last->next = datum;
1972 } else {
1973 rc = -ENOMEM;
1974 ft = kmemdup(&key, sizeof(key), GFP_KERNEL);
1975 if (!ft)
1976 goto out;
1977
1978 rc = hashtab_insert(&p->filename_trans, ft, datum,
1979 filenametr_key_params);
1980 if (rc)
1981 goto out;
1982 name = NULL;
1983
1984 rc = ebitmap_set_bit(&p->filename_trans_ttypes,
1985 key.ttype, 1);
1986 if (rc)
1987 return rc;
1988 }
1989 }
1990 kfree(name);
1991 return ebitmap_set_bit(&datum->stypes, stype - 1, 1);
1992
1993 out:
1994 kfree(ft);
1995 kfree(name);
1996 kfree(datum);
1997 return rc;
1998 }
regards,
dan carpenter
