On Thu, 11 Oct 2012 00:42:56 +0400 Cyrill Gorcunov <[email protected]> wrote:
> The free_pid_ns function done in recursion fashion: > > free_pid_ns(parent) > put_pid_ns(parent) > kref_put(&ns->kref, free_pid_ns); > free_pid_ns > > thus if there was a huge nesting of namespaces the userspace > may trigger avalanche calling of free_pid_ns leading to > kernel stack exhausting and a panic eventually. > > This patch turns the recursion into iterative loop. > > v5 (from oleg@): > - Drop @ret variable > - Make put_pid_ns non-inline since it grows in size, > in turn make free_pid_ns static OK, let's try that. I'll sit on this until -rc2 to give it a bit of time to cook. A -stable backport might be needed. What capabilities does userspace need to be able to trigger the kernel stack overflow? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
