diff --git a/drivers/cube/cubelinux_store.rs b/drivers/cube/cubelinux_store.rs
index dfe224192..18de5b2d9 100644
--- a/drivers/cube/cubelinux_store.rs
+++ b/drivers/cube/cubelinux_store.rs
@@ -4168,6 +4168,23 @@ impl kernel::InPlaceModule for CubeStoreModule {
         pr_info!("cubelinux: store reader registered at /dev/cubelinux\n");
         // SAFETY: called exactly once, in the module initializer, before anything can take it.
         unsafe { SPACE_STARTS.init() };
+        // STORE_FILE needs the same treatment, and it was the one that went without.
+        //
+        // The failure mode is why it hid for so long. A zeroed mutex satisfies the uncontended
+        // fast path — the count reads 0, which means "unlocked" — so one writer at a time works
+        // perfectly and nothing looks wrong. The first *contended* lock takes
+        // __mutex_lock_slowpath, which splices the task into the mutex's wait list; that list is
+        // uninitialised, so its head is NULL and the splice stores through it. A write to address
+        // 0 in kernel mode, after which the task returns with interrupts disabled and
+        // preemption held, which is a machine that cannot panic, log, or recover.
+        //
+        // Found by verify-file-store.sh MODE=race: twelve concurrent puts to a store that is a
+        // file on the root filesystem oopsed in cubelinux_store::store_file, while twelve
+        // sequential ones passed with exact log accounting. The same signature is on the box,
+        // where the store had several writers: a hard freeze with no panic despite panic=30, and
+        // a journal that simply stops.
+        // SAFETY: called exactly once, in the module initializer, before anything can take it.
+        unsafe { STORE_FILE.init() };
         try_pin_init!(Self {
             _miscdev <- MiscDeviceRegistration::register(MiscDeviceOptions {
                 name: c_str!("cubelinux"),