selftests/landlock: Test SCOPE_SIGNAL on the SIGIO/fowner pgid path

Browse source

Add regression tests for the LANDLOCK_SCOPE_SIGNAL handling of the
asynchronous SIGIO delivery path (fcntl(F_SETOWN)) with a process-group
owner.

sigio_to_pgid_members covers the bypass: a sandboxed process at the head
of its process group's PGID hlist (the default after fork()) arms
F_SETOWN(-pgrp) + O_ASYNC and triggers the fan-out; the in-domain owner
must be signaled (proving the trigger fired) while the non-sandboxed
member of the group, outside the domain, must not.

sigio_to_pgid_self covers the same-process guarantee: the owner is
registered from a sandboxed non-leader thread, whose domain differs from
the thread-group leader the kernel signals for a process-group owner.
That leader belongs to the owner's own process and must still be
signaled.

Without the fix the first test sees the out-of-domain member signaled
and the second sees the owner's own leader denied.

Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://patch.msgid.link/43370e89f7a896a583bf33d1cd171d02630e61bf.1780614610.git.hexlabsecurity@proton.me
[mic: Fix comment]
Signed-off-by: Mickaël Salaün <mic@digikod.net>

...

This commit is contained in:

Bryam Vargas 2026-06-04 23:17:05 +00:00 • committed by Mickaël Salaün

parent 4b80320ca7

commit 76579d09be

No known key found for this signature in database

GPG key ID: E5E3D0E88C82F6D2

1 changed files with 182 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

182

tools/testing/selftests/landlock/scoped_signal_test.c

View file