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| author | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2025-06-10 19:34:48 +0200 |
|---|---|---|
| committer | Joel Fernandes <joelagnelf@nvidia.com> | 2025-06-20 15:31:48 -0400 |
| commit | 33b6a1f155d627f5bd80c7485c598ce45428f74f (patch) | |
| tree | dc4a2892a5c619284e704d16dcb5fd67d4a362f7 | |
| parent | 11313e2f78128c948e9b4eb58b3dacfc30964700 (diff) | |
rcu: Return early if callback is not specified
Currently the call_rcu() API does not check whether a callback
pointer is NULL. If NULL is passed, rcu_core() will try to invoke
it, resulting in NULL pointer dereference and a kernel crash.
To prevent this and improve debuggability, this patch adds a check
for NULL and emits a kernel stack trace to help identify a faulty
caller.
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
| -rw-r--r-- | kernel/rcu/tree.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e8a4b720d7d2..14d4499c6fc3 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3072,6 +3072,10 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) /* Misaligned rcu_head! */ WARN_ON_ONCE((unsigned long)head & (sizeof(void *) - 1)); + /* Avoid NULL dereference if callback is NULL. */ + if (WARN_ON_ONCE(!func)) + return; + if (debug_rcu_head_queue(head)) { /* * Probable double call_rcu(), so leak the callback. |