Merge v7.1.4linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 19 insertions, 1 deletions

diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
index 912cb805caf5..fc97dd873974 100644
--- a/rust/kernel/block/mq/gen_disk.rs
+++ b/rust/kernel/block/mq/gen_disk.rs
@@ -150,6 +150,19 @@ impl GenDiskBuilder {
         // SAFETY: `gendisk` is a valid pointer as we initialized it above
         unsafe { (*gendisk).fops = &TABLE };
 
+        let cleanup_failure = ScopeGuard::new_with_data((gendisk, data), |(gendisk, data)| {
+            // SAFETY: `gendisk` came from `__blk_mq_alloc_disk()` above and
+            // has not been added to the VFS on this cleanup path.
+            unsafe { bindings::put_disk(gendisk) };
+            // SAFETY: `data` came from `into_foreign()` above and has not been
+            // converted back on this cleanup path.
+            drop(unsafe { T::QueueData::from_foreign(data) });
+        });
+
+        // The failure guard now owns both pieces of cleanup; the early guard
+        // must not run on this path anymore.
+        recover_data.dismiss();
+
         let mut writer = NullTerminatedFormatter::new(
             // SAFETY: `gendisk` points to a valid and initialized instance. We
             // have exclusive access, since the disk is not added to the VFS
@@ -172,7 +185,7 @@ impl GenDiskBuilder {
             },
         )?;
 
-        recover_data.dismiss();
+        cleanup_failure.dismiss();
 
         // INVARIANT: `gendisk` was initialized above.
         // INVARIANT: `gendisk` was added to the VFS via `device_add_disk` above.
@@ -215,6 +228,11 @@ impl<T: Operations> Drop for GenDisk<T> {
         // to the VFS.
         unsafe { bindings::del_gendisk(self.gendisk) };
 
+        // SAFETY: By type invariant, `self.gendisk` was added to the VFS, so
+        // `put_disk()` must follow `del_gendisk()` to drop the final gendisk
+        // reference and trigger the remaining release path.
+        unsafe { bindings::put_disk(self.gendisk) };
+
         // SAFETY: `queue.queuedata` was created by `GenDiskBuilder::build` with
         // a call to `ForeignOwnable::into_foreign` to create `queuedata`.
         // `ForeignOwnable::from_foreign` is only called here.