Bug #19593: Crash due to throw data set as cause

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 3.0: REQUIRED, 3.1: DONE, 3.2: DONE

[peterzhu2118 (Peter Zhu)]

GitHub PR: https://github.com/ruby/ruby/pull/7696

rb_ec_setup_exception did not check if errinfo is a throw_data. This can cause crashes in code since it is assumed that id_cause is an object.

We saw a crash in show_cause due to id_cause of errinfo being a throw_data. It crashes on rb_obj_is_kind_of since it cannot be called on T_IMEMO objects.

Unfortunately, we couldn't find a reproduction script, however we debugged the core dump and rb_ec_setup_exception is the only place where id_cause is assigned from errinfo without checking if it is a throw_data.

0x0000556c5708e6dd in sigsegv (sig=11, info=0x7f301befa3f0, ctx=0x7f301befa2c0) at signal.c:964
0x00007f301d046420 in <signal handler called> () at /lib/x86_64-linux-gnu/libpthread.so.0
class_search_class_ancestor (c=139844586301760, cl=<optimized out>) at object.c:810
rb_obj_is_kind_of (obj=obj@entry=139839221734880, c=139844586301760) at object.c:861
0x0000556c56f2f00f in show_cause
    (errinfo=errinfo@entry=139838840645160, str=str@entry=139839221730520, opt=139839221730480, highlight=0, reverse=reverse@entry=0, backtrace_limit=backtrace_limit@entry=-1, shown_causes=0x7ffe9d1a2d68) at ./include/ruby/internal/special_consts.h:175

[peterzhu2118 (Peter Zhu)]

• Backport changed from 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN to 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED

[peterzhu2118 (Peter Zhu)]

• Status changed from Open to Closed

Applied in changeset git|02a7e12b80823919fb614ad3ea6241d5115d14fe.

---

Ensure throw data is not set as cause

[Bug #19593]

rb_ec_setup_exception did not check if errinfo is a throw_data. This can
cause crashes in code since it is assumed that id_cause is an object.

We saw a crash in show_cause due to id_cause of errinfo being a
throw_data. It crashes on rb_obj_is_kind_of since it cannot be called on
T_IMEMO objects.

Unfortunately, we couldn't find a reproduction script, however we
debugged the core dump and rb_ec_setup_exception is the only place where
id_cause is assigned from errinfo without checking if it is a
throw_data.

0x0000556c5708e6dd in sigsegv (sig=11, info=0x7f301befa3f0, ctx=0x7f301befa2c0) at signal.c:964
0x00007f301d046420 in <signal handler called> () at /lib/x86_64-linux-gnu/libpthread.so.0
class_search_class_ancestor (c=139844586301760, cl=<optimized out>) at object.c:810
rb_obj_is_kind_of (obj=obj@entry=139839221734880, c=139844586301760) at object.c:861
0x0000556c56f2f00f in show_cause
    (errinfo=errinfo@entry=139838840645160, str=str@entry=139839221730520, opt=139839221730480, highlight=0, reverse=reverse@entry=0, backtrace_limit=backtrace_limit@entry=-1, shown_causes=0x7ffe9d1a2d68) at ./include/ruby/internal/special_consts.h:175

Co-Authored-By: Jean Boussier [e-mail]

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED to 3.0: REQUIRED, 3.1: REQUIRED, 3.2: DONE

ruby_3_2 5fc9825ccf651664c547b1822c7f753464e27f06 merged revision(s) 02a7e12b80823919fb614ad3ea6241d5115d14fe.

[usa (Usaku NAKAMURA)]

• Backport changed from 3.0: REQUIRED, 3.1: REQUIRED, 3.2: DONE to 3.0: REQUIRED, 3.1: DONE, 3.2: DONE

ruby_3_1 c96ef4eee6b27796bb15ba161ef936998acbcf96 merged revision(s) 02a7e12b80823919fb614ad3ea6241d5115d14fe.