1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 01666979beac..de5c16c6b6ec 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1696,7 +1696,12 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
                                 CLONE_NEWNET))
                 goto bad_unshare_out;
 
-        if (unshare_flags & CLONE_SYSVSEM)
+        /*
+         * CLONE_NEWIPC must also detach from the undolist: after switching
+         * to a new ipc namespace, the semaphore arrays from the old
+         * namespace are unreachable.
+         */
+        if (unshare_flags & (CLONE_NEWIPC|CLONE_SYSVSEM))
                 do_sysvsem = 1;
         if ((err = unshare_thread(unshare_flags)))
                 goto bad_unshare_out;