dcavalca / rpms / systemd

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From b2d259a82329e37b0f369e9951f19a067cb8bfb4 Mon Sep 17 00:00:00 2001
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From: Sam James <sam@gentoo.org>
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Date: Fri, 18 Nov 2022 07:18:18 +0000
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Subject: [PATCH] nspawn: allow sched_rr_get_interval_time64 through seccomp
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 filter
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We only allow a selected subset of syscalls from nspawn containers
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and don't list any time64 variants (needed for 32-bit arches when
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built using TIME_BITS=64, which is relatively new).
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We allow sched_rr_get_interval which cpython's test suite makes
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use of, but we don't allow sched_rr_get_interval_time64.
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The test failures when run in an arm32 nspawn container on an arm64 host
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were as follows:
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```
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======================================================================
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ERROR: test_sched_rr_get_interval (test.test_posix.PosixTester.test_sched_rr_get_interval)
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----------------------------------------------------------------------
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Traceback (most recent call last):
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  File "/var/tmp/portage/dev-lang/python-3.11.0_p1/work/Python-3.11.0/Lib/test/test_posix.py", line 1180, in test_sched_rr_get_interval
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    interval = posix.sched_rr_get_interval(0)
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               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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PermissionError: [Errno 1] Operation not permitted
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```
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Then strace showed:
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```
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sched_rr_get_interval_time64(0, 0xffbbd4a0) = -1 EPERM (Operation not permitted)
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```
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This appears to be the only time64 syscall that isn't already included one of
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the sets listed in nspawn-seccomp.c that has a non-time64 variant. Checked
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over each of the time64 syscalls known to systemd and verified that none
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of the others had a non-time64-variant whitelisted in nspawn other than
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sched_rr_get_interval.
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Bug: https://bugs.gentoo.org/880131
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(cherry picked from commit b9e7f22c2d80930cad36ae53e66e42a2996dca4a)
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Related: #2138081
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---
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 src/nspawn/nspawn-seccomp.c | 1 +
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 1 file changed, 1 insertion(+)
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diff --git a/src/nspawn/nspawn-seccomp.c b/src/nspawn/nspawn-seccomp.c
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index 77f4c2ac88..27044fadd2 100644
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--- a/src/nspawn/nspawn-seccomp.c
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+++ b/src/nspawn/nspawn-seccomp.c
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@@ -88,6 +88,7 @@ static int add_syscall_filters(
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                 { 0,                  "sched_getparam"         },
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                 { 0,                  "sched_getscheduler"     },
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                 { 0,                  "sched_rr_get_interval"  },
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+                { 0,                  "sched_rr_get_interval_time64" },
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                 { 0,                  "sched_yield"            },
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                 { 0,                  "seccomp"                },
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                 { 0,                  "sendfile"               },