#1134384 _exit uses NR_exit_group, leading to SIGKILL in seccomp

Package:
libc6
Source:
libc6
Description:
GNU C Library: Shared libraries
Submitter:
Simon Richter
Date:
2026-04-20 06:19:02 UTC
Severity:
normal
Tags:
#1134384#5
Date:
2026-04-19 11:31:42 UTC
From:
To:
Hi,

I have an application that uses seccomp in strict mode. When the
application is finished, it uses the _exit(2) system call to terminate, as
documented in seccomp(2). glibc however uses NR_exit_group, which is a
seccomp violation, so the process is ended with SIGKILL instead.

   Simon
#1134384#10
Date:
2026-04-19 11:53:29 UTC
From:
To:
Hi,

Yes, glibc does that since version 2.3 in order to terminate all
threads. I fail to see why it's a glibc issue though, this looks like
more a seccomp decision to not allow this syscall in strict mode.

Regards
Aurelien
#1134384#15
Date:
2026-04-20 05:22:05 UTC
From:
To:
reassign 1134384 manpages-dev
retitle 1134384 Document _exit(2) pitfall with seccomp(2)
tags 1134384 +patch
found 6.9.1-1
thanks

I guess the most sensible thing we can do here is document it.

   Simon