This patch fixes copy_namespaces()'s error path.
when new nsproxy (new_ns) is created pointers to namespaces (ipc, uts)
are copied from the old nsproxy. Later in copy_utsname, copy_ipcs, etc.
according namespaces are get-ed. On error path needed namespaces are
put-ed, so there's no need to put new nsproxy itelf as it woud cause
putting namespaces for the second time.
Found when incorporating namespaces into OpenVZ kernel.
Signed-off-by: Pavel Emelianov <[email protected]>
---
nsproxy.c | 2 +-
1 files changed, 1 insertion(+), 1 deletion(-)
--- ./kernel/nsproxy.c.veboot 2006-08-30 17:48:59.000000000 +0400
+++ ./kernel/nsproxy.c 2006-08-31 10:54:56.000000000 +0400
@@ -115,7 +115,7 @@ out_uts:
put_namespace(new_ns->namespace);
out_ns:
tsk->nsproxy = old_ns;
- put_nsproxy(new_ns);
+ kfree(new_ns);
goto out;
}
Quoting Pavel ([email protected]):
> This patch fixes copy_namespaces()'s error path.
>
> when new nsproxy (new_ns) is created pointers to namespaces (ipc, uts)
> are copied from the old nsproxy. Later in copy_utsname, copy_ipcs, etc.
> according namespaces are get-ed. On error path needed namespaces are
> put-ed, so there's no need to put new nsproxy itelf as it woud cause
> putting namespaces for the second time.
>
> Found when incorporating namespaces into OpenVZ kernel.
>
> Signed-off-by: Pavel Emelianov <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
> ---
>
> nsproxy.c | 2 +-
> 1 files changed, 1 insertion(+), 1 deletion(-)
>
> --- ./kernel/nsproxy.c.veboot 2006-08-30 17:48:59.000000000 +0400
> +++ ./kernel/nsproxy.c 2006-08-31 10:54:56.000000000 +0400
> @@ -115,7 +115,7 @@ out_uts:
> put_namespace(new_ns->namespace);
> out_ns:
> tsk->nsproxy = old_ns;
> - put_nsproxy(new_ns);
> + kfree(new_ns);
> goto out;
> }
Yes, thanks.
The logic has subtly changed since the last version I'd sent out. I
have tests which should have caught this, and need to start firing off
jobs to periodically test them against -mm.
In fact I notice that it is currently no longer putting old_ns on the
error path. Seems to me the following patch should be needed on top
of yours.
Meanwhile I'll start firing off a test against v2.6.18-rc4-mm3.
thanks,
-serge
>From c4d187c3c1534c22e7879d52eeceed55412c9559 Mon Sep 17 00:00:00 2001
From: Serge E. Hallyn <[email protected]>
Date: Thu, 31 Aug 2006 06:54:15 -0500
Subject: [PATCH 1/1] nsproxy: free the old_ns on copy_namespaces error
copy_namespaces increments the usage count on old_ns at top.
On successful exit it properly decrements that usage count.
On error path it failed to do so.
Signed-off-by: Serge E. Hallyn <[email protected]>
---
kernel/nsproxy.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index e25d97c..575155a 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -121,6 +121,7 @@ out_uts:
out_ns:
tsk->nsproxy = old_ns;
kfree(new_ns);
+ put_nsproxy(old_ns);
goto out;
}
--
1.4.2