lftp crashes while mirroring https

[Chris Cheney]

Binary package hint: lftp

While trying to mirror some files for testing purposes I noticed that lftp crashed, it appears to happen every time after some non-determined amount of download of files. Note - the username and password for the site have been scrubbed.

--

lftp https://username:<email address hidden>/canonical/pool/public/
cd ok, cwd=/canonical/pool/public
lftp <email address hidden>:/canonical/pool/public> mirror
mirror: Fatal error: gnutls_record_send: The specified session has been invalidated for some reason.
Segmentation fault (core dumped)24832 (79%) 244.6K/s eta:3s [Receiving data]

--

Backtrace:

#0 0x00007fb3dfedbd50 in strlen () from /lib/libc.so.6
No symbol table info available.
#1 0x00000000004408bc in xstring::set (this=0x188e460,
    s=0x23 <Address 0x23 out of bounds>) at xstring.cc:106
No locals.
#2 0x0000000000444fe8 in Buffer::SetError (this=0x23,
    e=0x23 <Address 0x23 out of bounds>, fatal=96) at buffer.cc:225
No locals.
#3 0x000000000049ae8a in IOBufferSSL::Get_LL (this=0x188e440, size=65536)
    at buffer_ssl.cc:92
 res = <value optimized out>
#4 0x000000000049af34 in IOBufferSSL::Do (this=0x188e440) at buffer_ssl.cc:57
 res = <value optimized out>
#5 0x000000000042ebcd in SMTask::Schedule () at SMTask.cc:238
 scan = (SMTask *) 0x188e440
 timer_timeout = <value optimized out>
 res = 1
#6 0x000000000040ba9d in Job::WaitDone (this=0x1382e80) at Job.cc:489
No locals.
#7 0x000000000040846c in main (argc=20523296, argv=<value optimized out>)
    at lftp.cc:465
 home = <value optimized out>
 exit_code = <value optimized out>

ProblemType: Bug
Architecture: amd64
Date: Wed Jun 17 14:59:27 2009
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/bin/lftp
Package: lftp 3.7.13-1
ProcEnviron:
 SHELL=/bin/bash
 LANG=en_US.UTF-8
ProcVersionSignature: Ubuntu 2.6.30-9.10-generic
SourcePackage: lftp
Uname: Linux 2.6.30-9-generic x86_64

[Chris Cheney (ccheney)]

It seems to segfault in the same manner with lftp 3.7.8-1 in jaunty.

[Chris Cheney (ccheney)]

I have also emailed the upstream author about this bug and am waiting to hear back from him.

[Cody A.W. Somerville (cody-somerville)]

This is still present in 3.7.15.

[Tony Mancill (tmancill)]

We've seen several crashes in production that are perhaps related. They occur during sftp puts and generate the following messages. We've been assuming that they're somehow data driven because they don't always occur.

Oct 10 04:14:53 snake kernel: [813728.417205] lftp[21822]: segfault at 7f1844e62792 ip 00007f1843a4e6df sp 00007fff2b8f0db0 error 6 in libc-2.11.1.so[7f18439c9000+17a000]

Sep 30 04:01:51 snake kernel: [511473.871916] lftp[31968]: segfault at 7f349c3d1a90 ip 00007f349afb314c sp 00007fff86c8f828 error 6 in libc-2.11.1.so[7f349af2c000+17a000]

OS: Ubuntu 10.04.1 LTS (server), x86_64
lftp version: 4.0.2-1ubuntu0.1

[Tony Mancill (tmancill)]

We're still seeing this when using sftp:// URLs on x86_64. The fact that this happens without any rhyme or reason makes lftp unusable for any sort of production/batch work. Here are some recent examples from dmesg:

[76722.114637] lftp[10068]: segfault at 7f8ba8de1000 ip 00007f8ba79c9150 sp 00007fffc80e7a28 error 4 in libc-2.11.1.so[7f8ba7942000+17a000]
[162010.835577] lftp[11787]: segfault at 7f1d2a8e9010 ip 00007f1d294be17c sp 00007fffb2e13a98 error 6 in libc-2.11.1.so[7f1d29437000+17a000]
[332589.719934] lftp[14127]: segfault at 7f9857f6b010 ip 00007f9856b4017c sp 00007ffffd267e08 error 6 in libc-2.11.1.so[7f9856ab9000+17a000]
[344808.826791] lftp[28432]: segfault at 7f1393705010 ip 00007f139241817c sp 00007fff47dd71b8 error 6 in libc-2.11.1.so[7f1392391000+17a000]

[Tony Mancill (tmancill)]

More of these random crashes... Adding them to the list because this time we saw "error 4" instead of "error 6" in the segfault.

[70197.782345] lftp[2492]: segfault at 7fe497b88185 ip 00007fe49673e70f sp 00007fffae9cb540 error 6 in libc-2.11.1.so[7fe4966b9000+17a000]
[161123.804785] lftp[31056]: segfault at 7fb4cb3a2000 ip 00007fb4c9f76150 sp 00007fff6595d048 error 4 in libc-2.11.1.so[7fb4c9eef000+17a000]

We would be willing to run an instrumented/debug version of lftp in production if it would help diagnose the problem. As it is, someone is getting paged every time one of these jobs fails.

[Noël Köthe (noel)]

I'm closing this old bug because I didn't get any equal problem reports in Debian and last comment/confirmation is more than 7 years old.

If you disagree please tell me/us.

thx for reporting.

[Tony Mancill (tmancill)]

On Fri, Aug 03, 2018 at 02:26:59AM -0000, Noël Köthe wrote:
> I'm closing this old bug because I didn't get any equal problem reports
> in Debian and last comment/confirmation is more than 7 years old.
>
> If you disagree please tell me/us.

Thanks for cleaning this up.