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-rw-r--r--debian/patches/block-ptrace-on-secret-daemons/Avoid-simple-memory-dumps-via-ptrace.patch89
1 files changed, 89 insertions, 0 deletions
diff --git a/debian/patches/block-ptrace-on-secret-daemons/Avoid-simple-memory-dumps-via-ptrace.patch b/debian/patches/block-ptrace-on-secret-daemons/Avoid-simple-memory-dumps-via-ptrace.patch
new file mode 100644
index 0000000..a1ce6ea
--- /dev/null
+++ b/debian/patches/block-ptrace-on-secret-daemons/Avoid-simple-memory-dumps-via-ptrace.patch
@@ -0,0 +1,89 @@
+From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+Date: Tue, 11 Aug 2015 20:28:26 -0400
+Subject: Avoid simple memory dumps via ptrace
+
+This avoids needing to setgid gpg-agent. It probably doesn't defend
+against all possible attacks, but it defends against one specific (and
+easy) one. If there are other protections we should do them too.
+
+This will make it slightly harder to debug the agent because the
+normal user won't be able to attach gdb to it directly while it runs.
+
+The remaining options for debugging are:
+
+ * launch the agent from gdb directly
+ * connect gdb to a running agent as the superuser
+
+Upstream bug: https://dev.gnupg.org/T1211
+---
+ agent/gpg-agent.c | 8 ++++++++
+ configure.ac | 2 +-
+ scd/scdaemon.c | 9 +++++++++
+ 3 files changed, 18 insertions(+), 1 deletion(-)
+
+diff --git a/agent/gpg-agent.c b/agent/gpg-agent.c
+index b167c34..5afcf11 100644
+--- a/agent/gpg-agent.c
++++ b/agent/gpg-agent.c
+@@ -50,6 +50,9 @@
+ # include <signal.h>
+ #endif
+ #include <npth.h>
++#ifdef HAVE_PRCTL
++# include <sys/prctl.h>
++#endif
+
+ #define INCLUDED_BY_MAIN_MODULE 1
+ #define GNUPG_COMMON_NEED_AFLOCAL
+@@ -1030,6 +1033,11 @@ main (int argc, char **argv )
+
+ early_system_init ();
+
++#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
++ /* Disable ptrace on Linux without sgid bit */
++ prctl(PR_SET_DUMPABLE, 0);
++#endif
++
+ /* Before we do anything else we save the list of currently open
+ file descriptors and the signal mask. This info is required to
+ do the exec call properly. We don't need it on Windows. */
+diff --git a/configure.ac b/configure.ac
+index 7a2d410..2d8b050 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -1426,7 +1426,7 @@ AC_CHECK_FUNCS([atexit canonicalize_file_name clock_gettime ctermid \
+ ftruncate funlockfile getaddrinfo getenv getpagesize \
+ getpwnam getpwuid getrlimit getrusage gettimeofday \
+ gmtime_r inet_ntop inet_pton isascii lstat memicmp \
+- memmove memrchr mmap nl_langinfo pipe raise rand \
++ memmove memrchr mmap nl_langinfo pipe prctl raise rand \
+ setenv setlocale setrlimit sigaction sigprocmask \
+ stat stpcpy strcasecmp strerror strftime stricmp \
+ strlwr strncasecmp strpbrk strsep strtol strtoul \
+diff --git a/scd/scdaemon.c b/scd/scdaemon.c
+index 5c519f8..cab66a0 100644
+--- a/scd/scdaemon.c
++++ b/scd/scdaemon.c
+@@ -37,6 +37,9 @@
+ #include <unistd.h>
+ #include <signal.h>
+ #include <npth.h>
++#ifdef HAVE_PRCTL
++# include <sys/prctl.h>
++#endif
+
+ #define INCLUDED_BY_MAIN_MODULE 1
+ #define GNUPG_COMMON_NEED_AFLOCAL
+@@ -446,6 +449,12 @@ main (int argc, char **argv )
+ npth_t pipecon_handler;
+
+ early_system_init ();
++
++#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
++ /* Disable ptrace on Linux without sgid bit */
++ prctl(PR_SET_DUMPABLE, 0);
++#endif
++
+ set_strusage (my_strusage);
+ gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
+ /* Please note that we may running SUID(ROOT), so be very CAREFUL