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author | Björn Gustavsson <bjorn@erlang.org> | 2021-09-09 09:28:57 +0200 |
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committer | Björn Gustavsson <bjorn@erlang.org> | 2022-03-01 08:12:45 +0100 |
commit | ebcbb97b4ec223464cac3d94375739a248ddef6e (patch) | |
tree | 8d280f74d4d659fc325f2f91ecf82b41e7339370 /erts/emulator/test/binary_SUITE.erl | |
parent | d469db4ddf72479a42b60f5337504fb53b65079e (diff) | |
download | erlang-ebcbb97b4ec223464cac3d94375739a248ddef6e.tar.gz |
Clean up size calculation for binary_to_term/1
This commit cleans up the size calculation phase of binary_to_term/1:
* Count sub terms in an **unsigned** 32-bit integer instead of in
an **signed** 32-bit integer to ensure that the counter wraps on
overflow. While the existing code worked on all platform we have
tested it on, signed overflow is is undefined behavior in the C
standard.
* Be paranoid and use the overflow-checking ADDTERM() macro for **all**
additions to the `term` variable.
* Reject lists and large tuples early if the rest of the binary being
decoded is obviously too short. (The same early rejection was already
done for maps.)
* Explicitly reject decoding maps with 2^31 or more elements on 64-bit
platforms (on 32-bit platforms there is already code to reject maps
with 2^30 or more elements). Decoding maps with that many elements
has never worked correctly, but would fail in random ways (because
the `term` variable would overflow and miscount the sub terms).
We considered counting sub terms in a 64-bit counter on 64-bit machines
to allow truly ginormous terms to be decoded, but decided that such terms
are probably a mistake and that it is better to reject them.
Diffstat (limited to 'erts/emulator/test/binary_SUITE.erl')
-rw-r--r-- | erts/emulator/test/binary_SUITE.erl | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/erts/emulator/test/binary_SUITE.erl b/erts/emulator/test/binary_SUITE.erl index 58d4f83a2c..c23b937fc3 100644 --- a/erts/emulator/test/binary_SUITE.erl +++ b/erts/emulator/test/binary_SUITE.erl @@ -1545,11 +1545,14 @@ test_terms(Test_Func) -> Test_Func("abcdef"), Test_Func([a, b, 1, 2]), Test_Func([a|b]), + Test_Func([make_port(), make_ref(), make_pid(), fun() -> ok end, + Very_Big | lists:seq(1, 75)]), Test_Func({}), Test_Func({1}), Test_Func({a, b}), Test_Func({a, b, c}), + Test_Func({make_port(), make_ref(), make_pid(), fun() -> ok end}), Test_Func(list_to_tuple(lists:seq(0, 255))), Test_Func(list_to_tuple(lists:seq(0, 256))), @@ -1600,9 +1603,11 @@ test_terms(Test_Func) -> Test_Func(<<42:10>>), Test_Func(list_to_bitstring([<<5:6>>|lists:seq(0, 255)])), + %% Funs in a list. Test_Func(F = fun(A) -> 42*A end), Test_Func(lists:duplicate(32, F)), + %% External funs in a list. Test_Func(FF = fun binary_SUITE:all/0), Test_Func(lists:duplicate(32, FF)), |