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authorEric W. Biederman <ebiederm@xmission.com>2013-03-30 09:35:18 +0100
committerEric W. Biederman <ebiederm@xmission.com>2013-08-27 03:42:15 +0200
commit4ce5d2b1a8fde84c0eebe70652cf28b9beda6b4e (patch)
tree08fa563457c4264fe48355e8d28c216c9a11664b /fs/pnode.h
parentkernel/nsproxy.c: Improving a snippet of code. (diff)
downloadlinux-4ce5d2b1a8fde84c0eebe70652cf28b9beda6b4e.tar.xz
linux-4ce5d2b1a8fde84c0eebe70652cf28b9beda6b4e.zip
vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces
Don't copy bind mounts of /proc/<pid>/ns/mnt between namespaces. These files hold references to a mount namespace and copying them between namespaces could result in a reference counting loop. The current mnt_ns_loop test prevents loops on the assumption that mounts don't cross between namespaces. Unfortunately unsharing a mount namespace and shared substrees can both cause mounts to propogate between mount namespaces. Add two flags CL_COPY_UNBINDABLE and CL_COPY_MNT_NS_FILE are added to control this behavior, and CL_COPY_ALL is redefined as both of them. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs/pnode.h')
-rw-r--r--fs/pnode.h5
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/pnode.h b/fs/pnode.h
index b091445c1c4a..59e7eda1851e 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -19,11 +19,14 @@
#define CL_EXPIRE 0x01
#define CL_SLAVE 0x02
-#define CL_COPY_ALL 0x04
+#define CL_COPY_UNBINDABLE 0x04
#define CL_MAKE_SHARED 0x08
#define CL_PRIVATE 0x10
#define CL_SHARED_TO_SLAVE 0x20
#define CL_UNPRIVILEGED 0x40
+#define CL_COPY_MNT_NS_FILE 0x80
+
+#define CL_COPY_ALL (CL_COPY_UNBINDABLE | CL_COPY_MNT_NS_FILE)
static inline void set_mnt_shared(struct mount *mnt)
{