Re: bin/49821: /bin/tar randomly coredumps when security.pax.aslr.enabled is set to 1

[Alexander Nasonov <alnsn%yandex.ru@localhost>]

Alexander Nasonov wrote:
> It's interesting that it crashed on a string containing "PQRVWAPAQARASH":
> 
> $ gdb - /var/crash/alnsn/tar.core  
> [New process 1]
> Core was generated by `tar'.
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0  0x00007f7ff7c02d60 in ?? ()
> (gdb) x/s 0x00007f7ff7c02d60
> 0x7f7ff7c02d60: "\234PQRVWAPAQARASH\213|$PH\213t$X\350J\003"
> (gdb) 

Passing /bin/tar to gdb reveals some information:

 $ gdb /bin/tar /var/crash/alnsn/tar.core 
 ...
 Type "apropos word" to search for commands related to "word"...
 Reading symbols from /bin/tar...(no debugging symbols found)...done.
 [New process 1]
 Core was generated by `tar'.
 Program terminated with signal SIGSEGV, Segmentation fault.
 #0  0x00007f7ff7c02d60 in _rtld_bind_start () from /libexec/ld.elf_so
 (gdb) bt
 #0  0x00007f7ff7c02d60 in _rtld_bind_start () from /libexec/ld.elf_so
 #1  0x00007c1751c1b000 in ?? ()
 #2  0x000000000000000a in ?? ()
 #3  0x000000000040384d in ar_start_gzip ()
 #4  0x0000000000403d65 in ar_open ()
 #5  0x0000000000406f51 in rd_start ()
 #6  0x00000000004054d0 in get_arc ()
 #7  0x0000000000405e9d in list ()
 #8  0x0000000000415a0e in main ()

Alex