diff options
Diffstat (limited to 'erts/doc')
| -rw-r--r-- | erts/doc/src/erlang.xml | 46 |
1 files changed, 44 insertions, 2 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 871fc0fd63..2541aa700b 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -342,8 +342,50 @@ iolist() = [char() | binary() | iolist()] <desc> <p>Returns an Erlang term which is the result of decoding the binary object <c>Binary</c>, which must be encoded - according to the Erlang external term format. See also - <seealso marker="#term_to_binary/1">term_to_binary/1</seealso>.</p> + according to the Erlang external term format.</p> + <warning> + <p>When decoding binaries from untrusted sources, consider using + <c>binary_to_term/2</c> to prevent denial of service attacks.</p> + </warning> + <p>See also + <seealso marker="#term_to_binary/1">term_to_binary/1</seealso> + and + <seealso marker="#binary_to_term/2">binary_to_term/2</seealso>.</p> + </desc> + </func> + <func> + <name>erlang:binary_to_term(Binary, Opts) -> term()</name> + <fsummary>Decode an Erlang external term format binary</fsummary> + <type> + <v>Opts = [safe]</v> + <v>Binary = ext_binary()</v> + </type> + <desc> + <p>As <c>binary_to_term/1</c>, but takes options that affect decoding + of the binary.</p> + <taglist> + <tag><c>safe</c></tag> + <item> + <p>Use this option when receiving binaries from an untrusted + source.</p> + <p>When enabled, it prevents decoding data that may be used to + attack the Erlang system. In the event of receiving unsafe + data, decoding fails with a badarg error.</p> + <p>Currently, this prevents creation of new atoms directly, + creation of new atoms indirectly (as they are embedded in + certain structures like pids, refs, funs, etc.), and creation of + new external function references. None of those resources are + currently garbage collected, so unchecked creation of them can + exhaust available memory.</p> + </item> + </taglist> + <p>Failure: <c>badarg</c> if <c>safe</c> is specified and unsafe data + is decoded.</p> + <p>See also + <seealso marker="#term_to_binary/1">term_to_binary/1</seealso>, + <seealso marker="#binary_to_term/1">binary_to_term/1</seealso>, + and <seealso marker="#list_to_existing_atom/1"> + list_to_existing_atom/1</seealso>.</p> </desc> </func> <func> |