Issue #22387 has been updated by nagachika (Tomoyuki Chikanaga). Backport changed from 3.3: DONTNEED, 3.4: REQUIRED, 4.0: DONE to 3.3: DONTNEED, 3.4: DONE, 4.0: DONE Merged into ruby_3_4 at https://github.com/ruby/ruby/commit/cc3e2b96872f7a91561c48ed814b5645a8d53030. BTW the corresponding commit hash on master branch is `323c1df196cd3ba12274757ff1739ca79b02e685`. ---------------------------------------- Bug #22387: str_shared_replace incorrectly recalculates termlen https://bugs.ruby-lang.org/issues/22387#change-119472 * Author: rwstauner (Randy Stauner) * Status: Closed * Backport: 3.3: DONTNEED, 3.4: DONE, 4.0: DONE ---------------------------------------- This ruby snippet crashes under ASan with a heap-buffer-overflow ```ruby s = ("\u{30AF}" * 7).encode("UTF-16LE").b s.force_encoding("UTF-16LE") s.encode!("UTF-8") # 21 bytes in a 22-byte malloc, capa now claims 22 s << "x" # fits, per capa, then NUL terminator written at [22] ``` str_shared_replace uses rb_enc_associate which recalculates termlen based on the old str even though the termlen of the new str was already used for the copy. We can just switch that to rb_enc_raw_set to fix. -- https://bugs.ruby-lang.org/