Bug #12441: Segfault in mod_exp

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux]
• Backport: 2.1: WONTFIX, 2.2: DONE, 2.3: DONE

[technion (Joshua Small)]

I have the piece of code crashing reliably.

#!/usr/bin/env ruby

require 'openssl'

p = 65997564567567456745676645367739412743227643334286989217363396439283464537000853588029739004855929104754800897261407081024749574299035313695899693187167


def mything(h)
  b = 43554325436535756
  k = h.to_bn.mod_exp(b, p)
end



h = 3007963317613531062721539798844764834140098543127007866692410407137612395983233591022449771190189492227443776860661459473931676217894527075146085609662899

puts mything h

I have written very similar pieces of code before without an issue but this but particular one seems to have hit something. I have attached a crash report.

[rhenium (Kazuki Yamaguchi)]

• Status changed from Open to Closed

The minimal reproducer:

123.to_bn.mod_exp(456, nil)

This is already (unintentionally) fixed in r55047.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN to 2.1: WONTFIX, 2.2: REQUIRED, 2.3: REQUIRED

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.1: WONTFIX, 2.2: REQUIRED, 2.3: REQUIRED to 2.1: WONTFIX, 2.2: REQUIRED, 2.3: DONE

ruby_2_3 r55906 merged revision(s) 55047.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.1: WONTFIX, 2.2: REQUIRED, 2.3: DONE to 2.1: WONTFIX, 2.2: DONE, 2.3: DONE

ruby_2_2 r55937 merged revision(s) 55047.