Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Alexei Starovoitov:

 - Replace bpf_map_kmalloc_node() with kmalloc_nolock() to fix kmemleak
   imbalance in tracking of bpf_async_cb structures (Alexei Starovoitov)

 - Make selftests/bpf arg_parsing.c more robust to errors (Andrii
   Nakryiko)

 - Fix redefinition of 'off' as different kind of symbol when I40E
   driver is builtin (Brahmajit Das)

 - Do not disable preemption in bpf_test_run (Sahil Chandna)

 - Fix memory leak in __lookup_instance error path (Shardul Bankar)

 - Ensure test data is flushed to disk before reading it (Xing Guo)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Fix redefinition of 'off' as different kind of symbol
  bpf: Do not disable preemption in bpf_test_run().
  bpf: Fix memory leak in __lookup_instance error path
  selftests: arg_parsing: Ensure data is flushed to disk before reading.
  bpf: Replace bpf_map_kmalloc_node() with kmalloc_nolock() to allocate bpf_async_cb structures.
  selftests/bpf: make arg_parsing.c more robust to crashes
  bpf: test_run: Fix ctx leak in bpf_prog_test_run_xdp error path

1 files changed, 14 insertions, 11 deletions

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index c9fab9a356df..8eb117c52817 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1215,13 +1215,20 @@ static void bpf_wq_work(struct work_struct *work)
 	rcu_read_unlock_trace();
 }
 
+static void bpf_async_cb_rcu_free(struct rcu_head *rcu)
+{
+	struct bpf_async_cb *cb = container_of(rcu, struct bpf_async_cb, rcu);
+
+	kfree_nolock(cb);
+}
+
 static void bpf_wq_delete_work(struct work_struct *work)
 {
 	struct bpf_work *w = container_of(work, struct bpf_work, delete_work);
 
 	cancel_work_sync(&w->work);
 
-	kfree_rcu(w, cb.rcu);
+	call_rcu(&w->cb.rcu, bpf_async_cb_rcu_free);
 }
 
 static void bpf_timer_delete_work(struct work_struct *work)
@@ -1230,13 +1237,13 @@ static void bpf_timer_delete_work(struct work_struct *work)
 
 	/* Cancel the timer and wait for callback to complete if it was running.
 	 * If hrtimer_cancel() can be safely called it's safe to call
-	 * kfree_rcu(t) right after for both preallocated and non-preallocated
+	 * call_rcu() right after for both preallocated and non-preallocated
 	 * maps.  The async->cb = NULL was already done and no code path can see
 	 * address 't' anymore. Timer if armed for existing bpf_hrtimer before
 	 * bpf_timer_cancel_and_free will have been cancelled.
 	 */
 	hrtimer_cancel(&t->timer);
-	kfree_rcu(t, cb.rcu);
+	call_rcu(&t->cb.rcu, bpf_async_cb_rcu_free);
 }
 
 static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u64 flags,
@@ -1270,11 +1277,7 @@ static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u
 		goto out;
 	}
 
-	/* Allocate via bpf_map_kmalloc_node() for memcg accounting. Until
-	 * kmalloc_nolock() is available, avoid locking issues by using
-	 * __GFP_HIGH (GFP_ATOMIC & ~__GFP_RECLAIM).
-	 */
-	cb = bpf_map_kmalloc_node(map, size, __GFP_HIGH, map->numa_node);
+	cb = bpf_map_kmalloc_nolock(map, size, 0, map->numa_node);
 	if (!cb) {
 		ret = -ENOMEM;
 		goto out;
@@ -1315,7 +1318,7 @@ static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u
 		 * or pinned in bpffs.
 		 */
 		WRITE_ONCE(async->cb, NULL);
-		kfree(cb);
+		kfree_nolock(cb);
 		ret = -EPERM;
 	}
 out:
@@ -1580,7 +1583,7 @@ void bpf_timer_cancel_and_free(void *val)
 	 * timer _before_ calling us, such that failing to cancel it here will
 	 * cause it to possibly use struct hrtimer after freeing bpf_hrtimer.
 	 * Therefore, we _need_ to cancel any outstanding timers before we do
-	 * kfree_rcu, even though no more timers can be armed.
+	 * call_rcu, even though no more timers can be armed.
 	 *
 	 * Moreover, we need to schedule work even if timer does not belong to
 	 * the calling callback_fn, as on two different CPUs, we can end up in a
@@ -1607,7 +1610,7 @@ void bpf_timer_cancel_and_free(void *val)
 		 * completion.
 		 */
 		if (hrtimer_try_to_cancel(&t->timer) >= 0)
-			kfree_rcu(t, cb.rcu);
+			call_rcu(&t->cb.rcu, bpf_async_cb_rcu_free);
 		else
 			queue_work(system_dfl_wq, &t->cb.delete_work);
 	} else {