Fatal glibc error: cannot get entropy for arc4random

[Elan Ruusamäe]

On 25.07.2024 11:05, Jan Palus wrote:
> Actually glibc-2.39-6 does not fallback to/dev/*random due to bug in
> arc4random fallback logic (return value checked for ENOSYS instead of
> errno).
>
> It was fixed on Jul 8 (glibc 2.40 does not suffer from it):
>
> https://sourceware.org/git/?p=glibc.git;a=commit;h=184b9e530e6326e668709826903b6d30dc6cac3f


upgraded glibc (glibc-2.40-2-th.x86_64). sshd starts up now, but logins 
still fail


$ ssh localhost
Connection closed by 127.0.0.1 port 22


Aug 20 13:34:44 localhost sshd-session[60905]: error: mm_reap: preauth 
child terminated by signal 31
Aug 20 13:34:44 localhost sshd[60900]: Session process 60905 unpriv 
child crash for connection from 127.0.0.1 to 127.0.0.1


$ ssh localhost
kex_exchange_identification: Connection closed by remote host

Aug 20 13:34:51 localhost sshd[60900]: drop connection #0 from 
[127.0.0.1]:63676 on [127.0.0.1]:22 penalty: caused crash


signal 31, I believe is SIGSYS:

31 SIGSYS     Dump        Bad system call                      No


package versions, just in case, again


glibc-2.40-2.x86_64: equal version installed, skipped
openssl-3.3.1-1.x86_64: equal version installed, skipped
libseccomp-2.5.5-1.x86_64: equal version installed, skipped
openssh-server-9.8p1-1.x86_64: equal version installed, skipped