[Pkg-gnupg-maint] Bug#771263: Bug#771263: gnupg fails (buffer overflow detected) to encrypt archive when called from duplicity

[NIIBE Yutaka]

On 11/28/2014 10:51 AM, Pandu Rao wrote:
> Package: gnupg
> Version: 1.4.18-4
> Severity: normal
[...]
>      *** buffer overflow detected ***: gpg terminated
>      ======= Backtrace: =========
>      /lib/x86_64-linux-gnu/libc.so.6(+0x7303f)[0x7f581fd9d03f]
>      /lib/x86_64-linux-gnu/libc.so.6(__fortify_fail+0x37)[0x7f581fe20147]
>      /lib/x86_64-linux-gnu/libc.so.6(+0xf4360)[0x7f581fe1e360]
>      /lib/x86_64-linux-gnu/libc.so.6(+0xf60b7)[0x7f581fe200b7]
>      gpg[0x4916c8]

Disassembling /usr/bin/gpg, it seems for me that it's __fdelt_chk
which caused this "buffer overflow":

  4916c3:       e8 e8 21 f7 ff          callq  4038b0 <__fdelt_chk at plt>
  4916c8:       8b 7c 24 28             mov    0x28(%rsp),%edi

One possibility is gnupg-1.4.x/cipher/rndlinux.c:rndlinux_gather_random.

When /dev/random (or /dev/urandom), is not accessible, for some
reason, I think that this buffer overflow is possible when FD_SET
(at line 125).

This is just a my theory.  It's pretty unusual you don't have
/dev/random (or /dev/urandom), so, I must be wrong.

But, just in case, could you please check your environment if /dev/random
is normal or not?
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