rtorrent crashes on startup

[Ignat Loskutov]

After some upgrade (I'm using 24.04, so `-D_FORITFY_SOURCE=3` applies), it seems that some increased level of libc hardening has been applied, leading to a crash inside the `Lockfile::try_lock()` function on startup.

There is an upstream commit addressing this issue (https://github.com/rakshasa/rtorrent/commit/92bec88d0904bfb31c808085c2fd0f22d0ec8db7) but no release has been formed to include it yet.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Evgeni Vasilev (aquilax)]

(gdb) bt
#0 __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized out>) at ./nptl/pthread_kill.c:44
#1 __pthread_kill_internal (signo=6, threadid=<optimized out>) at ./nptl/pthread_kill.c:78
#2 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at ./nptl/pthread_kill.c:89
#3 0x00007ffff764526e in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#4 0x00007ffff76288ff in __GI_abort () at ./stdlib/abort.c:79
#5 0x00007ffff76297b6 in __libc_message_impl (fmt=fmt@entry=0x7ffff77ce765 "*** %s ***: terminated\n") at ../sysdeps/posix/libc_fatal.c:132
#6 0x00007ffff7736c19 in __GI___fortify_fail (msg=msg@entry=0x7ffff77ce74c "buffer overflow detected") at ./debug/fortify_fail.c:24
#7 0x00007ffff77365d4 in __GI___chk_fail () at ./debug/chk_fail.c:28
#8 0x00007ffff7737db5 in ___snprintf_chk (s=<optimized out>, maxlen=maxlen@entry=255, flag=flag@entry=2, slen=<optimized out>, format=format@entry=0x555555646372 ":+%i\n")
    at ./debug/snprintf_chk.c:29
#9 0x00005555555cbce1 in snprintf (__fmt=<optimized out>, __n=<optimized out>, __s=<optimized out>, __s=<optimized out>, __n=<optimized out>, __fmt=<optimized out>)
    at /usr/include/x86_64-linux-gnu/bits/stdio2.h:54
#10 utils::Lockfile::try_lock (this=0x5555556dbd40) at utils/lockfile.cc:101
#11 core::DownloadStore::enable (lock=<optimized out>, this=0x5555556dbd20) at core/download_store.cc:74
#12 Control::initialize (this=0x5555556d7480) at /usr/src/rtorrent-0.9.8-1build3/src/control.cc:115
#13 0x00005555555947af in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/rtorrent-0.9.8-1build3/src/main.cc:469

[Frédéric Giquel (fredericgiquel)]

I'm facing the same crash when I use the "-s" option of rtorrent on Ubuntu 24.04.

So I tried to recompile the package after applyng the patch from upstream suggested in the original post. It fixes the crash.

[Russell Phillips (ignissport)]

Seconded. Doing an "apt source rtorrent", applying this patch, building and installing fixes the issue for me.

Rakshasa hasn't done an official release since 2019, and this commit has been sitting in trunk for over a year. It would be nice to see this patch expedited. I can't tell how long we'll be waiting for the next upstream release.