[tor-bugs] #33346 [Core Tor/Tor]: Seccomp soft fail (no write) in 0.4.2.6
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Sun Feb 16 00:49:53 UTC 2020
#33346: Seccomp soft fail (no write) in 0.4.2.6
-----------------------------+------------------------------
Reporter: subjectfrosting | Owner: (none)
Type: defect | Status: new
Priority: Medium | Component: Core Tor/Tor
Version: 0.4.2.6 | Severity: Normal
Keywords: | Actual Points:
Parent ID: | Points:
Reviewer: | Sponsor:
-----------------------------+------------------------------
I've upgraded to 0.4.2.6 (as a good software user, but also because I
noticed the seccomp changes).
Tor successfully starts with seccomp, but 'soft fails' because it can't
write to its data directory (here: /var/lib/tor/data). Tor has permissions
to write to this directory - fine with Sandbox 0.
Log:
{{{
# cat /var/log/tor/log
Feb 16 00:46:56.000 [notice] Tor 0.4.2.6 opening new log file.
Feb 16 00:46:56.000 [notice] Parsing GEOIP IPv4 file /usr/share/tor/geoip.
Feb 16 00:46:57.000 [notice] Parsing GEOIP IPv6 file
/usr/share/tor/geoip6.
Feb 16 00:46:57.000 [notice] Bootstrapped 0% (starting): Starting
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/cached-
certs": Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/cached-
consensus" for mmap(): Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/unverified-
consensus" for mmap(): Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/cached-
microdesc-consensus" for mmap(): Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/unverified-
microdesc-consensus" for mmap(): Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/cached-
microdescs" for mmap(): Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/cached-
microdescs.new": Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/cached-
descriptors" for mmap(): Operation not permitted
Feb 16 00:46:57.000 [warn] Could not open "/var/lib/tor/data/cached-
extrainfo" for mmap(): Operation not permitted
Feb 16 00:46:57.000 [notice] Starting with guard context "default"
Feb 16 00:46:58.000 [warn] Couldn't open "/var/lib/tor/data/state.tmp"
(/var/lib/tor/data/state) for writing: Operation not permitted
Feb 16 00:46:58.000 [warn] Unable to write state to file
"/var/lib/tor/data/state"; will try again later
Feb 16 00:46:58.000 [notice] Bootstrapped 5% (conn): Connecting to a relay
Feb 16 00:46:58.000 [notice] Bootstrapped 10% (conn_done): Connected to a
relay
Feb 16 00:46:58.000 [notice] Bootstrapped 14% (handshake): Handshaking
with a relay
Feb 16 00:46:58.000 [notice] Bootstrapped 15% (handshake_done): Handshake
with a relay done
Feb 16 00:46:58.000 [notice] Bootstrapped 20% (onehop_create):
Establishing an encrypted directory connection
Feb 16 00:46:58.000 [notice] Bootstrapped 25% (requesting_status): Asking
for networkstatus consensus
Feb 16 00:46:58.000 [notice] Bootstrapped 30% (loading_status): Loading
networkstatus consensus
Feb 16 00:46:59.000 [warn] Couldn't open "/var/lib/tor/data/unverified-
microdesc-consensus.tmp" (/var/lib/tor/data/unverified-microdesc-
consensus) for writing: Operation not permitted
Feb 16 00:46:59.000 [notice] I learned some more directory information,
but not enough to build a circuit: We have no usable consensus.
Feb 16 00:46:59.000 [notice] Bootstrapped 40% (loading_keys): Loading
authority key certs
Feb 16 00:46:59.000 [warn] Couldn't open "/var/lib/tor/data/cached-
certs.tmp" (/var/lib/tor/data/cached-certs) for writing: Operation not
permitted
Feb 16 00:46:59.000 [warn] Error writing certificates to disk.
Feb 16 00:46:59.000 [warn] Could not open "/var/lib/tor/data/unverified-
microdesc-consensus" for mmap(): Operation not permitted
Feb 16 00:46:59.000 [notice] I learned some more directory information,
but not enough to build a circuit: We have no usable consensus.
}}}
==== Appendix ====
===== Environment =====
{{{
Tor: 0.4.2.6
OS: Gentoo arm64
Hardware: Raspberry Pi 4
Kernel: 4.19.102-v8+ (RPi base)
}}}
===== Other info =====
When running 0.4.2.5, I experienced a crash with seccomp (possibly related
to #27315)?
{{{
# tor
Feb 16 00:37:42.963 [notice] Tor 0.4.2.5 running on Linux with Libevent
2.1.8-stable, OpenSSL 1.1.1d, Zlib 1.2.11, Liblzma N/A, and Libzstd N/A.
Feb 16 00:37:42.963 [notice] Tor can't help you if you use it wrong! Learn
how to be safe at https://www.torproject.org/download/download#warning
Feb 16 00:37:42.963 [notice] Read configuration file "/etc/tor/torrc".
Feb 16 00:37:42.966 [notice] Opening Socks listener on 127.0.0.1:9050
Feb 16 00:37:42.966 [notice] Opened Socks listener on 127.0.0.1:9050
============================================================ T= 1581813463
(Sandbox) Caught a bad syscall attempt (syscall unlinkat)
tor(+0x1cd714)[0x5571820714]
linux-vdso.so.1(__kernel_rt_sigreturn+0x0)[0x7f8bde0658]
/lib64/libc.so.6(unlink+0x30)[0x7f8b8058d8]
tor(run_tor_main_loop+0x74)[0x55716ae874]
tor(tor_run_main+0x11c)[0x55716aead4]
tor(tor_main+0x50)[0x55716ad458]
tor(main+0x24)[0x55716acf74]
/lib64/libc.so.6(__libc_start_main+0xe4)[0x7f8b758cac]
tor(+0x59fd0)[0x55716acfd0]
}}}
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/33346>
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