rsync 3.2.7 hangs when --usermap is used and receiver is not a super-user

[Tomasz Chmielewski]

On 2023-03-09 08:15, Francis.Montagnac at inria.fr wrote:
> Hi.
> 
> On Wed, 08 Mar 2023 22:21:28 +0100 Tomasz Chmielewski via rsync wrote:
> 
>> After upgrading to rsync 3.2.7, the following command hangs forever
>> (using "--usermap" causes the hang; without "--usermap" it doesn't
>> hang):
> 
>> rsync -v -p -e --usermap user:user /etc/services user at remote:
> 
> This command is incorrect: the -e option needs a command.
> 
> Without -e this command works for me on Fedora-37 with
> rsync-3.2.7-1.fc37.x86_64

I've removed some excessive parameters and filenames from my original 
ones, but left over the "-e" which is indeed not needed there.

There seems to be some other requirements for it to be reproduced:

1) transfer on the localhost, Ubuntu 22.10 (rsync 
3.2.7-0ubuntu0.22.10.1) - NOT reproducible:

$ rsync -v -p --usermap tch:tch /etc/services tch at localhost:/tmp
services

sent 160 bytes  received 149 bytes  618.00 bytes/sec
total size is 12,813  speedup is 41.47
$


2) transfer from Debian 11 (rsync 3.2.3-4+deb11u1) to Ubuntu 22.10 
(rsync 3.2.7-0ubuntu0.22.10.1) - reproducible, hangs:

# rsync -p --usermap user:user /etc/services user at 10.42.0.47:/tmp
[...never returns, needs ctrl+C...]

Also hangs when the user provided to --usermap does not exist

# rsync -p --usermap does-not-exist:does-not-exist /etc/services 
tch at 10.42.0.47:/tmp
Unknown --usermap name on receiver: does-not-exist
[...never returns, needs ctrl+C...]


3) transfer from 22.10 (rsync 3.2.7-0ubuntu0.22.10.1) to Ubuntu 22.04 
(rsync 3.2.7-0ubuntu0.22.04.2) - NOT reproducible:

$ rsync -p --usermap does-not-exist:does-not-exist /etc/services 
tch at 192.168.1.23:/tmp
Unknown --usermap name on receiver: does-not-exist
$


4) transfer from Debian 11 (rsync 3.2.3-4+deb11u1) to Ubuntu 22.04 
(rsync 3.2.7-0ubuntu0.22.04.2) - reproducible, hangs:

# rsync -p --usermap does-not-exist:does-not-exist /etc/services 
tch at 192.168.1.23:/tmp
Unknown --usermap name on receiver: does-not-exist
[...never returns, needs ctrl+C...]



So from the tests above, it hangs with rsync 3.2.3 on the sender and 
rsync 3.2.7 on the receiver. I'll run some more tests.


Tomasz Chmielewski