From: David Gibson <david@gibson.dropbear.id.au>
To: Stefano Brivio <sbrivio@redhat.com>
Cc: passt-dev@passt.top, David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 04/10] Remove unhelpful drop_caps() call in pasta_start_ns()
Date: Tue, 11 Oct 2022 16:40:12 +1100 [thread overview]
Message-ID: <20221011054018.1449506-5-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20221011054018.1449506-1-david@gibson.dropbear.id.au>
drop_caps() has a number of bugs which mean it doesn't do what you'd
expect. However, even if we fixed those, the call in pasta_start_ns()
doesn't do anything useful:
* In the common case, we're UID 0 at this point. In this case drop_caps()
doesn't accomplish anything, because even with capabilities dropped, we
are still privileged.
* When attaching to an existing namespace with --userns or --netns-only
we might not be UID 0. In this case it's too early to drop all
capabilities: we need at least CAP_NET_ADMIN to configure the
tap device in the namespace.
Remove this call - we will still drop capabilities a little later in
sandbox().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
pasta.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/pasta.c b/pasta.c
index 1ad63fb..4ff322c 100644
--- a/pasta.c
+++ b/pasta.c
@@ -223,8 +223,6 @@ void pasta_start_ns(struct ctx *c, int argc, char *argv[])
exit(EXIT_FAILURE);
}
- drop_caps();
-
NS_CALL(pasta_wait_for_ns, c);
}
--
@@ -223,8 +223,6 @@ void pasta_start_ns(struct ctx *c, int argc, char *argv[])
exit(EXIT_FAILURE);
}
- drop_caps();
-
NS_CALL(pasta_wait_for_ns, c);
}
--
2.37.3
next prev parent reply other threads:[~2022-10-11 5:40 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-11 5:40 [PATCH 00/10] Fixes and cleanups for capability handling David Gibson
2022-10-11 5:40 ` [PATCH 01/10] test: Move slower tests to end of test run David Gibson
2022-10-11 5:40 ` [PATCH 02/10] pasta: More general way of starting spawned shell as a login shell David Gibson
2022-10-13 2:16 ` Stefano Brivio
2022-10-13 8:22 ` David Gibson
2022-10-13 9:48 ` Stefano Brivio
2022-10-13 23:24 ` David Gibson
2022-10-11 5:40 ` [PATCH 03/10] pasta_start_ns() always ends in parent context David Gibson
2022-10-11 5:40 ` David Gibson [this message]
2022-10-11 5:40 ` [PATCH 05/10] Clarify various self-isolation steps David Gibson
2022-10-13 2:17 ` Stefano Brivio
2022-10-13 8:31 ` David Gibson
2022-10-13 12:49 ` Stefano Brivio
2022-10-13 23:25 ` David Gibson
2022-10-11 5:40 ` [PATCH 06/10] Replace FWRITE with a function David Gibson
2022-10-13 2:17 ` Stefano Brivio
2022-10-13 8:51 ` David Gibson
2022-10-11 5:40 ` [PATCH 07/10] isolation: Replace drop_caps() with a version that actually does something David Gibson
2022-10-13 2:18 ` Stefano Brivio
2022-10-13 9:44 ` David Gibson
2022-10-13 4:01 ` Stefano Brivio
2022-10-13 13:08 ` Stefano Brivio
2022-10-13 16:37 ` Stefano Brivio
2022-10-13 23:42 ` David Gibson
2022-10-11 5:40 ` [PATCH 08/10] isolation: Prevent any child processes gaining capabilities David Gibson
2022-10-13 2:17 ` Stefano Brivio
2022-10-13 9:33 ` David Gibson
2022-10-13 9:50 ` Stefano Brivio
2022-10-11 5:40 ` [PATCH 09/10] isolation: Only configure UID/GID mappings in userns when spawning shell David Gibson
2022-10-13 2:18 ` Stefano Brivio
2022-10-13 9:36 ` David Gibson
2022-10-11 5:40 ` [PATCH 10/10] Rename pasta_setup_ns() to pasta_spawn_cmd() David Gibson
2022-10-13 2:44 ` [PATCH 00/10] Fixes and cleanups for capability handling Stefano Brivio
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