[pkg-gnupg-maint] Bug#878952: scdaemon: avoid ptrace on scdaemon?

[Daniel Kahn Gillmor]

Package: scdaemon
Version: 2.2.1-2
Severity: normal

Debian currently ships with
debian/patches/block-ptrace-on-agent/Avoid-simple-memory-dumps-via-ptrace.patch,
which blocks a simple attack where any process running as the same
user can trace its system calls and memory.  This isn't bulletproof,
but it raises the bar against a casual attacker.

However, we're not shipping the same protection for scdeamon.

This means, for example, that a process running as the same user could
attach strace to scdaemon and snoop PINs or traffic sent to and from
the smartcard.

Should we add a similar "prctl(PR_SET_DUMPABLE, 0)" to scdaemon as
well?

        --dkg

-- System Information:
Debian Release: buster/sid
  APT prefers testing-debug
  APT policy: (500, 'testing-debug'), (500, 'testing'), (500, 'oldstable'), (200, 'unstable-debug'), (200, 'unstable'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.13.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages scdaemon depends on:
ii  gpg-agent      2.2.1-2
ii  libassuan0     2.4.3-3
ii  libc6          2.24-17
ii  libgcrypt20    1.7.9-1
ii  libgpg-error0  1.27-3
ii  libksba8       1.3.5-2
ii  libnpth0       1.5-2
ii  libusb-1.0-0   2:1.0.21-2

scdaemon recommends no packages.

scdaemon suggests no packages.

-- no debconf information