[tor-bugs] #9602 [Tor]: Segfault in Tor 0.2.4.1[67]-rc after SIGUSR1

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#9602: Segfault in Tor 0.2.4.1[67]-rc after SIGUSR1
---------------------------+--------------------------------
     Reporter:  pyllyukko  |      Owner:
         Type:  defect     |     Status:  needs_information
     Priority:  normal     |  Milestone:  Tor: 0.2.4.x-final
    Component:  Tor        |    Version:  Tor: 0.2.4.16-rc
   Resolution:             |   Keywords:
Actual Points:             |  Parent ID:
       Points:             |
---------------------------+--------------------------------

Comment (by pyllyukko):

 Bit more details:

 {{{
 (gdb) x/4a $ebp
 0xbff95778:     0xbff957b0      0xb728c048 <__vsnprintf_chk+232>
 0xbff957b0      0xb777c173
 (gdb) x/20s 0xb777c173
 0xb777c173:     "%s:%u"
 0xb777c179:     "TLS channel (no connection)"
 0xb777c195:     "TLS channel (connection %llu)"
 0xb777c1b3:     "conn->chan == chan"
 0xb777c1c6:     "chan->conn == conn"
 0xb777c1d9:     "non-versioned"
 0xb777c1e7:     "a v1"
 0xb777c1ec:     "behind"
 0xb777c1f3:     "ahead"
 0xb777c1f9:     "<none>"
 0xb777c200:     "chan->conn->link_proto >= 3"
 0xb777c21c:     " NETINFO"
 0xb777c225:     " AUTH_CHALLENGE"
 0xb777c235:     " CERTS"
 0xb777c23c:     " VERSIONS"
 0xb777c246:     "chan->conn->handshake_state"
 0xb777c262:     "Sending cells:"
 0xb777c271:     "Couldn't send versions cell"
 0xb777c28d:     "Couldn't send certs cell"
 0xb777c2a6:     "Couldn't send netinfo cell"
 (gdb) x/5i $pc
 => 0xb71d66ae <vfprintf+6398>:  repnz scas %es:(%edi),%al
    0xb71d66b0 <vfprintf+6400>:  movl   $0x0,-0x494(%ebp)
    0xb71d66ba <vfprintf+6410>:  not    %ecx
    0xb71d66bc <vfprintf+6412>:  lea    -0x1(%ecx),%edi
    0xb71d66bf <vfprintf+6415>:  jmp    0xb71d6412 <vfprintf+5730>
 (gdb) info reg edi
 edi            0xcccccccc       -858993460
 (gdb) info reg al
 al             0x0      0
 }}}

 Hope this helps. Maybe you can start looking the code, from where this is
 called and try to find the bug from there. I'll start digging through
 Tor's code as soon as I get the change, but I'm definitely not an expert,
 so no guarantees on any results :)

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9602#comment:15>
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