Fix NULL pointer passed to strlcpy from zap_lookup_impl()

Clang's static analyzer pointed out that whenever zap_lookup_by_dnode() is called, we have the following stack where strlcpy() is passed a NULL pointer for realname from zap_lookup_by_dnode(): strlcpy() zap_lookup_impl() zap_lookup_norm_by_dnode() zap_lookup_by_dnode() Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Richard Yao <[email protected]> Closes openzfs#14044
tonyhutter · Dec 1, 2022 · bbec0e6 · bbec0e6
1 parent a5f17a9
commit bbec0e6
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/module/zfs/zap_micro.c b/module/zfs/zap_micro.c
@@ -988,8 +988,10 @@ zap_lookup_impl(zap_t *zap, const char *name,
 			} else {
 				*(uint64_t *)buf =
 				    MZE_PHYS(zap, mze)->mze_value;
-				(void) strlcpy(realname,
-				    MZE_PHYS(zap, mze)->mze_name, rn_len);
+				if (realname != NULL)
+					(void) strlcpy(realname,
+					    MZE_PHYS(zap, mze)->mze_name,
+					    rn_len);
 				if (ncp) {
 					*ncp = mzap_normalization_conflict(zap,
 					    zn, mze);