Bug#977245: openssh-server: Kernel error after big rsync or scp

Package: openssh-server
Version: 1:8.4p1-3
Severity: important
X-Debbugs-Cc: [email protected]

Dear Maintainer,

After attempting to scp or rsync a directory with many large-ish files
(20-600M) to a remote host, the remote machine will crash. This hasn't happened
with smaller file transfers; only when the directory contains gigabytes of
data, after about 3GB have been copied. I tried once to scp a similar ammount
of data from a different client to the same machine, with the same result. The
commands used were:

	scp -r ./localdirectory jgmanilla@remotehost:~/
	rsync -avP ./localdirectory jgmanilla@remotehost:~/

If you happened to be logged into an ssh session, you may get the following
message before the system goes down:

	Message from syslogd@localhost at Dec 12 16:22:24 ...
	 kernel:[  406.101940] Internal error: Oops: 96000004 [#1] SMP

	Message from syslogd@localhost at Dec 12 16:22:24 ...
	 kernel:[  406.130105] Code: b9402a62 f9405e63 8b020014 dac00e81 (f8626814) 

Expected outcome was for scp and rsync to complete their file transfers
with no errors.

The hardware of the remote machine was a RockPro64.
The client operating systems tested were Gentoo and Arch linux.

-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: arm64 (aarch64)

Kernel: Linux 5.9.0-4-arm64 (SMP w/6 CPU threads)
Locale: LANG=es_MX.UTF-8, LC_CTYPE=es_MX.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages openssh-server depends on:
ii  adduser                3.118
ii  debconf [debconf-2.0]  1.5.74
ii  dpkg                   1.20.5
ii  libaudit1              1:2.8.5-3.1+b1
ii  libc6                  2.31-5
ii  libcom-err2            1.45.6-1
ii  libcrypt1              1:4.4.17-1
ii  libgssapi-krb5-2       1.18.3-4
ii  libkrb5-3              1.18.3-4
ii  libpam-modules         1.3.1-5
ii  libpam-runtime         1.3.1-5
ii  libpam0g               1.3.1-5
ii  libselinux1            3.1-2+b2
ii  libssl1.1              1.1.1h-1
ii  libsystemd0            247.1-3
ii  libwrap0               7.6.q-31
ii  lsb-base               11.1.0
ii  openssh-client         1:8.4p1-3
ii  openssh-sftp-server    1:8.4p1-3
ii  procps                 2:3.3.16-5
ii  runit-helper           2.10.2
ii  ucf                    3.0043
ii  zlib1g                 1:1.2.11.dfsg-2

Versions of packages openssh-server recommends:
ii  libpam-systemd [logind]  247.1-3
ii  ncurses-term             6.2+20201114-1
ii  xauth                    1:1.0.10-1

Versions of packages openssh-server suggests:
pn  molly-guard   <none>
pn  monkeysphere  <none>
pn  ssh-askpass   <none>
pn  ufw           <none>

-- debconf information excluded