[BRLTTY] Crash in TTY, was: Crash of BRLTTY in X session

[Sebastian Humenda]

Hi

Samuel Thibault schrieb am 11.03.2025, 17:21 +0100:
>> > Is this patch going to be applied to master eventually?
>> 
>> No, it's asan which will be fixed eventually :)
>
>(if you want to track it it's on 
>https://github.com/llvm/llvm-project/issues/124484 )

Thanks!

As a follow-up, I have got another crash, the log is below. It seems to be
related to BRLAPI, maybe even the bug that I was looking for originally.
At a quick glance, I haven't seen the cause in the code.

Thanks for looking into this!
Sebastian
===
brltty: cannot open process identifier file: /: Is a directory
=================================================================
==343413==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6040004657f8 at pc 0x7feef303928e bp 0x7feeebdb72b0 sp 0x7feeebdb6a60
WRITE of size 80 at 0x6040004657f8 thread T2
    #0 0x7feef303928d in __interceptor_memset ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:799
    #1 0x518557 in handleWrite brlapi_server.c:1301
    #2 0x51fb85 in processRequest brlapi_server.c:2785
    #3 0x51fb85 in handleTtyFds brlapi_server.c:3599
    #4 0x51fa76 in handleTtyFds brlapi_server.c:3617
    #5 0x521633 in runServer brlapi_server.c:3944
    #6 0x452577 in runThread thread.c:46
    #7 0x7feef08a81c3 in start_thread nptl/pthread_create.c:442
    #8 0x7feef092885b in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
0x6040004657f8 is located 0 bytes to the right of 40-byte region [0x6040004657d0,0x6040004657f8)
allocated by thread T2 here:
    #0 0x7feef30ae7ff in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
    #1 0x51d205 in allocBrailleWindow brlapi_server.c:584
    #2 0x51d205 in handleEnterTtyMode brlapi_server.c:887
Thread T2 created by T0 here:
    #0 0x7feef3056716 in __interceptor_pthread_create ../../../../src/libsanitizer/asan/asan_interceptors.cpp:216
    #1 0x451e61 in createActualThread thread.c:75
    #2 0x451e61 in createSignalSafeThread thread.c:114
SUMMARY: AddressSanitizer: heap-buffer-overflow ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:799 in __interceptor_memset
Shadow bytes around the buggy address:
  0x0c0880084aa0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c0880084ab0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c0880084ac0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c0880084ad0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c0880084ae0: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
=>0x0c0880084af0: fa fa fd fd fd fd fd fa fa fa 00 00 00 00 00[fa]
  0x0c0880084b00: fa fa 00 00 00 00 00 fa fa fa fd fd fd fd fd fa
  0x0c0880084b10: fa fa fd fd fd fd fd fa fa fa 00 00 00 00 00 fa
  0x0c0880084b20: fa fa 00 00 00 00 01 fa fa fa fd fd fd fd fd fa
  0x0c0880084b30: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x0c0880084b40: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd 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
==343413==ABORTING