From 07e03761a7fc1626a6a74ed957e117f56981558c Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Mon, 18 Mar 2024 13:22:17 +0000 Subject: libstdc++: Fix infinite loop in std::binomial_distribution [PR114359] The multiplication (4 * _M_t * __1p) can wraparound to zero if _M_t is unsigned and 4 * _M_t wraps to zero. The third operand has type double, so do the second multiplication first, so that we aren't multiplying integers. libstdc++-v3/ChangeLog: PR libstdc++/114359 * include/bits/random.tcc (binomial_distribution::param_type): Ensure arithmetic is done as type double. * testsuite/26_numerics/random/binomial_distribution/114359.cc: New test. --- .../26_numerics/random/binomial_distribution/114359.cc | 12 ++++++++++++ 1 file changed, 12 insertions(+) create mode 100644 libstdc++-v3/testsuite/26_numerics/random/binomial_distribution/114359.cc (limited to 'libstdc++-v3/testsuite/26_numerics') diff --git a/libstdc++-v3/testsuite/26_numerics/random/binomial_distribution/114359.cc b/libstdc++-v3/testsuite/26_numerics/random/binomial_distribution/114359.cc new file mode 100644 index 0000000..c1e4c38 --- /dev/null +++ b/libstdc++-v3/testsuite/26_numerics/random/binomial_distribution/114359.cc @@ -0,0 +1,12 @@ +// { dg-do run { target c++11 } } + +// Bug 114359 - std::binomial_distribution hangs in infinite loop + +#include + +int main() +{ + std::default_random_engine g{}; + std::binomial_distribution b(1U << 30); + b(g); // hangs forever +} -- cgit v1.1