Bug#790236: openssh-server: sshd segfaults afer many unsuccesfull login attempts
Package: openssh-server
Version: 1:6.0p1-4+deb7u2
Severity: normal
Dear Maintainer,
yesterday my ssh server segfaulted with the following message:
[4868342.681831] sshd[3996]: segfault at 7fa8c721c6a0 ip
00007faac7259ddb sp 00007ffc696e59d0 error 4 in sshd[7faac7249000+7c000]
This happened never before and the machine is on 24/7 with a public
accessible ssh port.
Immediately before I have 10k entries in sshd.log which say
Jun 26 23:04:30 localhost sshd[7994]: User root from XXX not allowed
because not listed in AllowUsers
Jun 26 23:04:30 localhost sshd[7994]: input_userauth_request: invalid
user root [preauth]
Jun 26 23:04:30 localhost sshd[7994]: Received disconnect from XXX: 11:
Bye Bye [preauth]
At that time neither the memory nor the disk was full.
My sshd.conf says
[...]
AllowUsers ... root@127.0.0.1 ...
PermitRootLogin without-password
[...]
Please tell me if I should provide more information.
-- System Information:
Debian Release: 7.8
APT prefers oldstable
APT policy: (500, 'oldstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 3.2.0-4-amd64 (SMP w/2 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash
Versions of packages openssh-server depends on:
ii adduser 3.113+nmu3
ii debconf [debconf-2.0] 1.5.49
ii dpkg 1.16.16
ii libc6 2.13-38+deb7u8
ii libcomerr2 1.42.5-1.1+deb7u1
ii libgssapi-krb5-2 1.10.1+dfsg-5+deb7u3
ii libkrb5-3 1.10.1+dfsg-5+deb7u3
ii libpam-modules 1.1.3-7.1
ii libpam-runtime 1.1.3-7.1
ii libpam0g 1.1.3-7.1
ii libselinux1 2.1.9-5
ii libssl1.0.0 1.0.1e-2+deb7u17
ii libwrap0 7.6.q-24
ii lsb-base 4.1+Debian8+deb7u1
ii openssh-client 1:6.0p1-4+deb7u2
ii procps 1:3.3.3-3
ii zlib1g 1:1.2.7.dfsg-13
Versions of packages openssh-server recommends:
ii ncurses-term 5.9-10
ii openssh-blacklist 0.4.1+nmu1
ii openssh-blacklist-extra 0.4.1+nmu1
ii xauth 1:1.0.7-1
Versions of packages openssh-server suggests:
pn molly-guard <none>
pn monkeysphere <none>
pn rssh <none>
pn ssh-askpass <none>
pn ufw <none>
-- debconf information:
ssh/vulnerable_host_keys:
ssh/new_config: true
* ssh/use_old_init_script: true
ssh/disable_cr_auth: false
ssh/encrypted_host_key_but_no_keygen:
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