mksh expand ASAN heap-buffer-overflow

[Fernando Muñoz]

ubuntu@bashfz:~/newmksh/mksh$ mksh -c 'echo ${0@#$0}'
=================================================================
==4807==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xf4d01559 at pc 0x56649efd bp 0xffe0e668 sp 0xffe0e658
READ of size 1 at 0xf4d01559 thread T0
    #0 0x56649efc (/usr/bin/mksh+0x7befc)

0xf4d01559 is located 0 bytes to the right of 9-byte region [0xf4d01550,0xf4d01559)
allocated by thread T0 here:
    #0 0xf7aae5bd in __interceptor_realloc (/lib/i386-linux-gnu/libasan.so.5+0x1125bd)
    #1 0x565df15d (/usr/bin/mksh+0x1115d)

SUMMARY: AddressSanitizer: heap-buffer-overflow (/usr/bin/mksh+0x7befc)
Shadow bytes around the buggy address:
  0x3e9a0250: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x3e9a0260: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x3e9a0270: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x3e9a0280: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x3e9a0290: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x3e9a02a0: fa fa fa fa fa fa fa fa fa fa 00[01]fa fa 00 01
  0x3e9a02b0: fa fa 00 01 fa fa 00 01 fa fa 00 fa fa fa 00 00
  0x3e9a02c0: fa fa 00 05 fa fa 00 04 fa fa fd fd fa fa fd fd
  0x3e9a02d0: fa fa fd fd fa fa fd fd fa fa fd fd fa fa fd fd
  0x3e9a02e0: fa fa fd fd fa fa fd fd fa fa fa fa fa fa fa fa
  0x3e9a02f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable: 00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone: fa
  Freed heap region: fd
  Stack left redzone: f1
  Stack mid redzone: f2
  Stack right redzone: f3
  Stack after return: f5
  Stack use after scope: f8
  Global redzone: f9
  Global init order: f6
  Poisoned by user: f7
  Container overflow: fc
  Array cookie: ac
  Intra object redzone: bb
  ASan internal: fe
  Left alloca redzone: ca
  Right alloca redzone: cb
  Shadow gap: cc
==4807==ABORTING

ubuntu@bashfz:~/newmksh/mksh$ valgrind ./mksh -c 'echo ${0@#$0}'
==4808== Memcheck, a memory error detector
==4808== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==4808== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==4808== Command: ./mksh -c echo\ ${0@#$0}
==4808==
==4808== Invalid read of size 1
==4808== at 0x118527: expand (eval.c:821)
==4808== by 0x11AABD: eval (eval.c:154)
==4808== by 0x11C630: execute (exec.c:124)
==4808== by 0x1335E1: shell (main.c:908)
==4808== by 0x10B118: main (main.c:704)
==4808== Address 0x4a36873 is 0 bytes after a block of size 11 alloc'd
==4808== at 0x483453B: malloc (in /usr/lib/i386-linux-gnu/valgrind/vgpreload_memcheck-x86-linux.so)
==4808== by 0x4836C88: realloc (in /usr/lib/i386-linux-gnu/valgrind/vgpreload_memcheck-x86-linux.so)
==4808== by 0x10B68C: aresize (lalloc.c:154)
==4808== by 0x1420F0: setstr (var.c:491)
==4808== by 0x14300F: isglobal (var.c:272)
==4808== by 0x14305D: global (var.c:238)
==4808== by 0x11A9E5: varsub (eval.c:1378)
==4808== by 0x11A9E5: expand (eval.c:390)
==4808== by 0x11AABD: eval (eval.c:154)
==4808== by 0x11C630: execute (exec.c:124)
==4808== by 0x1335E1: shell (main.c:908)
==4808== by 0x10B118: main (main.c:704)
==4808==
==4808== Invalid read of size 1
==4808== at 0x1173CF: expand (eval.c:869)
==4808== by 0x11AABD: eval (eval.c:154)
==4808== by 0x11C630: execute (exec.c:124)
==4808== by 0x1335E1: shell (main.c:908)
==4808== by 0x10B118: main (main.c:704)
==4808== Address 0x4a36873 is 0 bytes after a block of size 11 alloc'd
==4808== at 0x483453B: malloc (in /usr/lib/i386-linux-gnu/valgrind/vgpreload_memcheck-x86-linux.so)
==4808== by 0x4836C88: realloc (in /usr/lib/i386-linux-gnu/valgrind/vgpreload_memcheck-x86-linux.so)
==4808== by 0x10B68C: aresize (lalloc.c:154)
==4808== by 0x1420F0: setstr (var.c:491)
==4808== by 0x14300F: isglobal (var.c:272)
==4808== by 0x14305D: global (var.c:238)
==4808== by 0x11A9E5: varsub (eval.c:1378)
==4808== by 0x11A9E5: expand (eval.c:390)
==4808== by 0x11AABD: eval (eval.c:154)
==4808== by 0x11C630: execute (exec.c:124)
==4808== by 0x1335E1: shell (main.c:908)
==4808== by 0x10B118: main (main.c:704)
==4808==

==4808==
==4808== HEAP SUMMARY:
==4808== in use at exit: 0 bytes in 0 blocks
==4808== total heap usage: 438 allocs, 438 frees, 30,013 bytes allocated
==4808==
==4808== All heap blocks were freed -- no leaks are possible
==4808==
==4808== For counts of detected and suppressed errors, rerun with: -v
==4808== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)

[Thorsten Glaser (mirabilos)]

fix is making it to the anoncvs and github mirrors within the hour