Segmentation fault downloading via sftp after Pkg.update()

[baumgold]

When downloading a file via sftp, the Multi finalizer seems to cause a Segmentation fault when calling curl_multi_cleanup here if (and only if) I run Pkg.update() prior to calling Downloads.download (note there is no seg-fault if I comment-out Pkg.update()). Steps to reproduce in Julia v1.7.3:

julia> using Pkg, Downloads

julia> Pkg.update()
    Updating registry at `~/.julia/registries/General.toml`
  No Changes to `~/.julia/environments/v1.7/Project.toml`
  No Changes to `~/.julia/environments/v1.7/Manifest.toml`

julia> Downloads.Curl.PROTOCOL_STATUS["sftp"] = Downloads.Curl.status_zero_ok # https://github.com/JuliaLang/Downloads.jl/pull/180
status_zero_ok (generic function with 1 method)

julia> ENV["JULIA_SSH_NO_VERIFY_HOSTS"] = "sftpng.cmegroup.com"
"sftpng.cmegroup.com"

julia> url = "sftp://<username>:<password>@sftpng.cmegroup.com/path/to/config.xml"
"sftp://<username>:<password>@sftpng.cmegroup.com/path/to/config.xml"

julia> Downloads.download(url)
"/tmp/jl_kxgYuA"

julia> # ^D

signal (11): Segmentation fault
in expression starting at none:0
mbedtls_aesni_crypt_ecb at ~/julia/julia-1.7.3/bin/../lib/julia/libmbedcrypto.so.5 (unknown line)
mbedtls_aes_crypt_ecb at ~/julia/julia-1.7.3/bin/../lib/julia/libmbedcrypto.so.5 (unknown line)
mbedtls_ctr_drbg_random_with_add at ~/julia/julia-1.7.3/bin/../lib/julia/libmbedcrypto.so.5 (unknown line)
mbedtls_ctr_drbg_random at ~/julia/julia-1.7.3/bin/../lib/julia/libmbedcrypto.so.5 (unknown line)
_libssh2_mbedtls_random at ~/julia/julia-1.7.3/bin/../lib/julia/libssh2.so.1 (unknown line)
_libssh2_transport_send at ~/julia/julia-1.7.3/bin/../lib/julia/libssh2.so.1 (unknown line)
_libssh2_channel_close at ~/julia/julia-1.7.3/bin/../lib/julia/libssh2.so.1 (unknown line)
_libssh2_channel_free at ~/julia/julia-1.7.3/bin/../lib/julia/libssh2.so.1 (unknown line)
libssh2_sftp_shutdown at ~/julia/julia-1.7.3/bin/../lib/julia/libssh2.so.1 (unknown line)
ssh_statemach_act at ~/julia/julia-1.7.3/bin/../lib/julia/libcurl.so (unknown line)
ssh_block_statemach.constprop.1 at ~/julia/julia-1.7.3/bin/../lib/julia/libcurl.so (unknown line)
Curl_disconnect at ~/julia/julia-1.7.3/bin/../lib/julia/libcurl.so (unknown line)
Curl_conncache_close_all_connections at ~/julia/julia-1.7.3/bin/../lib/julia/libcurl.so (unknown line)
curl_multi_cleanup at ~/julia/julia-1.7.3/bin/../lib/julia/libcurl.so (unknown line)
curl_multi_cleanup at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/LibCURL/src/lC_curl_h.jl:214 [inlined]
done! at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Downloads/src/Curl/Multi.jl:28
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1788 [inlined]
run_finalizer at /buildworker/worker/package_linux64/build/src/gc.c:278
jl_gc_run_finalizers_in_list at /buildworker/worker/package_linux64/build/src/gc.c:365
run_finalizers at /buildworker/worker/package_linux64/build/src/gc.c:394 [inlined]
jl_gc_run_all_finalizers at /buildworker/worker/package_linux64/build/src/gc.c:482
jl_atexit_hook at /buildworker/worker/package_linux64/build/src/init.c:240
jl_repl_entrypoint at /buildworker/worker/package_linux64/build/src/jlapi.c:702
main at julia (unknown line)
__libc_start_main at /lib64/libc.so.6 (unknown line)
unknown function (ip: 0x400808)
Allocations: 5343807 (Pool: 5340217; Big: 3590); GC: 8
Segmentation fault (core dumped)

The sftp site is publicly available (link). If you prefer not to use JULIA_SSH_NO_VERIFY_HOSTS then SSH keys can be installed as follows

ssh-keyscan sftpng.cmegroup.com >> ~/.ssh/known_hosts

More information:

julia> using InteractiveUtils

julia> versioninfo()
Julia Version 1.7.3
Commit 742b9abb4d (2022-05-06 12:58 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Xeon(R) Gold 6136 CPU @ 3.00GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, skylake-avx512)
Environment:
  JULIA_NUM_THREADS = 4

[baumgold]

Is anyone able to help me debug this? I'm not familiar enough with libcurl to quickly pinpoint the problem.

[StefanKarpinski]

Can you try a newer Julia like 1.8.1?

[StefanKarpinski]

This works for me on 1.8.1 (with the status_ok patch) and on master it works without the status_ok patch.

[staticfloat]

@baumgold I noticed that you accidentally exposed your SFTP credentials in your report; I've edited them out, but you should rotate your password to be safe.