[tor-relays] Tor 0.4.7.7 Segmentation fault on Ubuntu 22.04 caused by "rseq"

[Xiaoqi Chen (Danny)]

Dear relay operators,

I recently upgraded one of my relays to Ubuntu 22.04 and now tor keeps
crashing. I debugged a little bit and saw the following error in the log.
It appears that it's due to seccomp not allowing "rseq" syscall, and
possibly related to the latest version of Glibc.

I temporarily mitigated the issue by turning off sandbox mode (remove
"Sandbox 1" in torrc). Does anyone know how to properly resolve the
crashing issue?

Cheers,
Danny Chen
--

$ sudo tor -f /etc/tor/torrc
May 07 02:10:46.831 [notice] Tor 0.4.7.7 running on Linux with Libevent
2.1.12-stable, OpenSSL 3.0.2, Zlib 1.2.11, Liblzma 5.2.5, Libzstd 1.4.8 and
Glibc 2.35 as libc.
......
May 07 02:10:46.833 [notice] Opening Directory listener on 0.0.0.0:8080
May 07 02:10:46.833 [notice] Opened Directory listener connection (ready)
on 0.0.0.0:8080
Fatal glibc error: rseq registration failed

============================================================ T=Fatal glibc
error: rseq registration failed
 1651889448
Tor 0.4.7.7 died: Caught signal 11
Fatal glibc error: rseq registration failed
Fatal glibc error: rseq registration failed
tor(+0xee525)[0x55c6431d6525]
/lib/x86_64-linux-gnu/libc.so.6(abort+0x178)[0x7fe6da9ee898]
/lib/x86_64-linux-gnu/libc.so.6(abort+0x178)[0x7fe6da9ee898]
/lib/x86_64-linux-gnu/libc.so.6(+0x8945c)[0x7fe6daa4f45c]
/lib/x86_64-linux-gnu/libc.so.6(+0x89770)[0x7fe6daa4f770]
/lib/x86_64-linux-gnu/libc.so.6(+0x94b31)[0x7fe6daa5ab31]
/lib/x86_64-linux-gnu/libc.so.6(+0x126a00)[0x7fe6daaeca00]
Fatal glibc error: rseq registration failed
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