• d-bugmail puremagic.com (31/57) Sep 14 2018 https://issues.dlang.org/show_bug.cgi?id=19247

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=19247

          Issue ID: 19247
           Summary: Segmentation fault when resolving address with
                    std.socket.getAddress inside a Fiber
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P1
         Component: phobos
          Assignee: nobody puremagic.com
          Reporter: zorael gmail.com

Manjaro/Arch x86_64. dmd 2.082, ldc v1.11 from repositories.

Resolving an invalid address with no dots, such as "asdf", causes a
segmentation fault. Resolving a nonexistent address throws an exception, as it
should, and valid addresses resolve fine.

Noteworthy is that it started after I moved the resolving into a function run
as a Generator Fiber. Calls to getAddress outside of it seem to work fine.
Unsure if that's relevant.

Tested on two machines running Linux, with dmd and ldc. On a Windows machine
however it properly threw a SocketOSException: getaddrinfo error: No such host
is known.

Reduced example (31 lines) is at the resolveseg branch of
https://github.com/zorael/kameloso.

 $ git clone https://github.com/zorael/kameloso.git -b resolveseg
 $ cd kameloso
 $ ./tester
 0x00007ffff7a583a8 in __res_context_hostalias () from /usr/lib/libresolv.so.2

Manually, invalid address:
 $ gdb --batch -ex run --args kameloso wefpok
 [Thread debugging using libthread_db enabled]
 Using host libthread_db library "/usr/lib/libthread_db.so.1".
 Attempting to resolve wefpok
 
 Program received signal SIGSEGV, Segmentation fault.
 0x00007ffff7a583a8 in __res_context_hostalias () from /usr/lib/libresolv.so.2

Manually, valid address:
 $ gdb --batch -ex run --args kameloso dlang.org
 [Thread debugging using libthread_db enabled]
 Using host libthread_db library "/usr/lib/libthread_db.so.1".
 Attempting to resolve dlang.org
 Success
 [Inferior 1 (process 15589) exited normally]

Random changes to the source makes it segfault in getenv in libc.so.6 instead.
For instance, version/comment out the foreach in resolveFiber in connection.d.

 (gdb) bt


/usr/lib/libresolv.so.2


/usr/lib/libnss_dns.so.2



_D3std6socket18getAddressInfoImplFMAxaMQePS4core3sys5posix5netdb8addrinfoZA
QCwQCv11AddressInfo () from /usr/lib/libphobos2.so.0.82
 [...]

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