I have started to notice this just the last week. My microdc2 is started with in a screen at the same time as my computer. I noticed that microdc2 sometime seems to hang and I also noticed that my hardened-kernel started to give messages about microdc2 segfaulting very often. I had not noticed this if I did not have the log messages from grsec telling me stuff segfaulted, however I do not think this is related to hardened. Now I was able to make microdc2 produce a corefile, and made a backtrace from it: #0 base_name (name=0x0) at basename.c:41 base = <value optimized out> p = <value optimized out> #1 0x0000000c9e5945b2 in open_upload_file_main (ucl=0xc9e856780, str=<value optimized out>, offset=0, type=DC_ADCGET_TTH) at user.c:607 st = {st_dev = 4008722732160, st_ino = 16412202259750788539, st_nlink = 54198543840, st_mode = 40, st_uid = 5, st_gid = 236108526, __pad0 = 0, st_rdev = 54213529888, st_size = 0, st_blksize = 3789574688816, st_blocks = 54198543840, st_atim = {tv_sec = 3788161155077, tv_nsec = 4008722732064}, st_mtim = {tv_sec = 40, tv_nsec = 0}, st_ctim = {tv_sec = 54199047192, tv_nsec = 54199047198}, __unused = {54196357192, 0, -2034541813958763077}} may_upload = true share_file = 0xc9f60c800 "`\302`\237\f" local_file = 0x0 conv_local_file = <value optimized out> res = <value optimized out> #2 0x0000000c9e595a06 in open_upload_file_adcget (ucl=0xc9e856780, buf=<value optimized out>, len=<value optimized out>) at user.c:776 filename = 0xc9f60d120 "MLUM3PJ6MBIHCJLLFDO3XETH6TVCVSX5QFCFZBQ" t = DC_ADCGET_TTH #3 user_handle_command (ucl=0xc9e856780, buf=<value optimized out>, len=<value optimized out>) at user.c:1187 startpos = <value optimized out> flags = <value optimized out> n_numbytes = 236108526 filename = 0xc9e83d41d "TTH/MLUM3PJ6MBIHCJLLFDO3XETH6TVCVSX5QFCFZBQ" numbytes = <value optimized out> n_startpos = 0 #4 0x0000000c9e59691b in user_input_available (get_fd=<value optimized out>, put_fd=<value optimized out>, addr=<value optimized out>, sock=<value optimized out>) at user.c:1225 start = 68 res = <value optimized out> #5 user_main (get_fd=<value optimized out>, put_fd=<value optimized out>, addr=<value optimized out>, sock=<value optimized out>) at user.c:1533 res_read_fds = {fds_bits = {524288, 0 <repeats 15 times>}} res_write_fds = {fds_bits = {0 <repeats 16 times>}} sigact = {__sigaction_handler = {sa_handler = 0x1, sa_sigaction = 0x1}, sa_mask = {__val = {0 <repeats 16 times>}}, sa_flags = 268435456, sa_restorer = 0} ucl = <value optimized out> #6 0x0000000c9e58c0d0 in user_connection_new (addr=0x3a55a7ec0d0, user_socket=-1) at main.c:405 uc = <value optimized out> get_fd = {15, 16} put_fd = {17, 18} #7 0x0000000c9e5890b7 in hub_handle_command () at hub.c:760 addr = {sin_family = 2, sin_port = 21463, sin_addr = {s_addr = 1933135967}, sin_zero = " U{\236\f\000\000"} hub_my_nick = 0xc9f6444c0 "xake_serv" #8 hub_input_available () at hub.c:1000 start = <value optimized out> c = <value optimized out> res = <value optimized out> #9 0x0000000c9e58d3bf in main (argc=<value optimized out>, argv=<value optimized out>) at main.c:1316 res_read_fds = {fds_bits = {512, 0 <repeats 15 times>}} res_write_fds = {fds_bits = {0 <repeats 16 times>}} tv = {tv_sec = 0, tv_usec = 630664} c = <value optimized out> config_file = 0x0 custom_config = <value optimized out> tmpdir = <value optimized out> sigact = {__sigaction_handler = {sa_handler = 0x1, sa_sigaction = 0x1}, sa_mask = {__val = {0 <repeats 16 times>}}, sa_flags = 268435456, sa_restorer = 0} Portage 2.1.9.42 (hardened/linux/amd64/no-multilib, gcc-4.4.5, glibc-2.11.3-r0, 2.6.37-hardened-r5 x86_64) ================================================================= System uname: Linux-2.6.37-hardened-r5-x86_64-AMD_Athlon-tm-_II_X2_245e_Processor-with-gentoo-2.0.2 Timestamp of tree: Sat, 26 Mar 2011 02:00:01 +0000 ccache version 2.4 [disabled] app-shells/bash: 4.1_p9 dev-lang/python: 2.7.1-r1, 3.1.3-r1 dev-util/ccache: 2.4-r9 sys-apps/baselayout: 2.0.2 sys-apps/openrc: 0.6.8 sys-apps/sandbox: 2.4 sys-devel/autoconf: 2.65-r1 sys-devel/automake: 1.11.1 sys-devel/binutils: 2.20.1-r1 sys-devel/gcc: 4.4.5 sys-devel/gcc-config: 1.4.1 sys-devel/libtool: 2.2.10 sys-devel/make: 3.81-r2 virtual/os-headers: 2.6.36.1 (sys-kernel/linux-headers) ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -pipe -march=native -mtune=native -ggdb" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/openvpn/easy-rsa" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-O2 -pipe -march=native -mtune=native -ggdb" DISTDIR="/var/portage/distfiles" FEATURES="assume-digests binpkg-logs buildpkg distlocks fixlafiles fixpackages news parallel-fetch protect-owned sandbox sfperms splitdebug strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox" FFLAGS="" GENTOO_MIRRORS="ftp://ftp.sunet.se/pub/os/Linux/distributions/gentoo ftp://ftp.df.lth.se/pub/gentoo/ ftp://mirror.mdfnet.se/gentoo/" LANG="sv_SE.UTF-8" LDFLAGS="-Wl,-O1 -Wl,--as-needed -Wl,-O1 -Wl,--sort-common -Wl,--warn-once,--hash-style=gnu" LINGUAS="sv" MAKEOPTS="-j10 -l10" PKGDIR="/var/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/var/portage" PORTDIR_OVERLAY="/var/overlays/mine" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="3dnow 3dnowext acl amd64 auto-hinter bash-completion berkdb bzip2 caps cli cracklib crypt cups cxx dri gdbm gmp hardened iconv idn ipv6 isc jpeg jpeg2k justify logrotate lzma mbox mmx mmxext modules mudflap ncurses nls nptl nptlonly offensive openmp pam pcre perl png pppd python readline session sse sse2 ssl svg sysfs tcpd tiff tproxy unicode urandom usb xinetd xorg zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ubx" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="sv" PHP_TARGETS="php5-3" QEMU_SOFTMMU_TARGETS="i386 x86_64" RUBY_TARGETS="ruby18" SANE_BACKENDS="niash" USERLAND="GNU" VIDEO_CARDS="none" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS
CCing treecleaners
Upstream looks dead for ages and most distributions already dropped it. I only see this debian package (from 2011) that contains a patch for fixing a segfault when a log file is specified in the config file :/ Anyway, here is the tarball for the case you want to try their patches and see if any of them helps you: http://http.debian.net/debian/pool/main/m/microdc2/microdc2_0.15.6-2.debian.tar.gz (under debian/patches directory)
commit 8409aa244ccd0c0445e10ee896bbae61df301d86 Author: Michał Górny <mgorny@gentoo.org> AuthorDate: Sun Jul 24 12:48:09 2016 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: Sun Jul 24 12:52:44 2016 net-p2p/microdc2: Remove last-rited pkg, #360631
