Bug #14893: Global buffer overflow in signm2signo of signal.c.

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN

[take-cheeze (Takeshi Watanabe)]

Found some memory error with address sanitizer:

==29152==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55fb96d91983 at pc 0x7f80615106c6 bp 0x7fff6ee86480 sp 0x7fff6ee85c28
    #1 0x55fb96aee1e7 in signm983 thread T0
    #0 0x7f80615106c5 in memcmp (/usr/lib/x86_64-linux-gnu/libasan.so.2+0x776c5)
    #1 0x55fb96aee1e7 in signm2signo /home/takeshi/dev/ruby/signal.c:262
    #2 0x55fb96af0e81 in trap_signm /home/takeshi/dev/ruby/signal.c:1262
    #3 0x55fb96af11c6 in sig_trap /home/takeshi/dev/ruby/signal.c:1378
    #4 0x55fb96bd36a9 in call_cfunc_m1 /home/takeshi/dev/ruby/vm_insnhelper.c:1739
    #5 0x55fb96bd54d4 in vm_call_cfunc_with_frame /home/takeshi/dev/ruby/vm_insnhelper.c:1934
    #6 0x55fb96bd581d in vm_call_cfunc /home/takeshi/dev/ruby/vm_insnhelper.c:1950
    #7 0x55fb96bd8a57 in vm_call_method_each_type /home/takeshi/dev/ruby/vm_insnhelper.c:2272
    #8 0x55fb96bd9c5e in vm_call_method /home/takeshi/dev/ruby/vm_insnhelper.c:2398
    #9 0x55fb96bda0ee in vm_call_general /home/takeshi/dev/ruby/vm_insnhelper.c:2441
    #10 0x55fb96bea238 in vm_exec_core /home/takeshi/dev/ruby/insns.def:779
    #11 0x55fb96c102cd in vm_exec /home/takeshi/dev/ruby/vm.c:1807
    #12 0x55fb96c126c8 in rb_iseq_eval_main /home/takeshi/dev/ruby/vm.c:2066
    #13 0x55fb968bca15 in ruby_exec_internal /home/takeshi/dev/ruby/eval.c:261
    #14 0x55fb968bcd58 in ruby_exec_node /home/takeshi/dev/ruby/eval.c:325
    #15 0x55fb968bccdc in ruby_run_node /home/takeshi/dev/ruby/eval.c:317
    #16 0x55fb968b7018 in main main.c:42
    #17 0x7f806050d82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #18 0x55fb968b6e18 in _start (/home/takeshi/dev/ruby/ruby+0xd1e18)

Seems like strlen(sigs->signm) may be shorter than len - prefix in some cases.
Made PR too for CI: https://github.com/ruby/ruby/pull/1904

[take-cheeze (Takeshi Watanabe)]

• File 1904.patch 1904.patch added

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset trunk|r63841.

---

signal.c: packed signals

• signal.c (signals): pack signal names instead of references.

• signal.c (signm2signo): also reject too long signal name.
  [ruby-core:87767] [Bug #14893]