Issue #20292 has been updated by k0kubun (Takashi Kokubun). Backport changed from 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: REQUIRED, 3.3: REQUIRED to 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: REQUIRED, 3.3: DONE ruby_3_3 commit:f12c947192aa47b355015384e5c82cbf674023f1 merged revision(s) commit:e04146129ec6898dd6a9739dad2983c6e9b68056. ---------------------------------------- Bug #20292: Abort ruby by `String#initialize` https://bugs.ruby-lang.org/issues/20292#change-108492 * Author: ksss (Yuki Kurihara) * Status: Closed * ruby -v: ruby 3.4.0dev (2024-02-22T06:43:46Z master e1c684e471) [arm64-darwin22] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: REQUIRED, 3.3: DONE ---------------------------------------- I found a code that causes an anomaly. ``` $ uname -a Darwin 20208671n 22.6.0 Darwin Kernel Version 22.6.0: Wed Oct 4 21:26:55 PDT 2023; root:xnu-8796.141.3.701.17~4/RELEASE_ARM64_T6020 arm64 $ ruby -v ruby 3.4.0dev (2024-02-22T06:43:46Z master e1c684e471) [arm64-darwin22] $ ruby -e '100.times { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa".__send__(:initialize, capacity: -1) }' ruby(13817,0x1f22b2080) malloc: Heap corruption detected, free list is damaged at 0x600000e27bc0 *** Incorrect guard value: 29830901955328 ruby(13817,0x1f22b2080) malloc: *** set a breakpoint in malloc_error_break to debug [1] 13817 abort ruby -e $ ruby -e '100.times { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa".__send__(:initialize, capacity: 0) }' # never return .... ``` My research indicates the following conditions. - String must be at least 64 characters long - Call `#initialize` with capacity: 0 or less - Repeat this several times. -- https://bugs.ruby-lang.org/