From c4c02084d6687d5cd5edccaf52cc45e5160f1184 Mon Sep 17 00:00:00 2001 From: Tomer Pomeranc Date: Wed, 12 Aug 2026 22:53:15 +0300 Subject: binder: fix leaked fd fixups on TF_UPDATE_TXN supersede When a TF_UPDATE_TXN transaction supersedes a pending async transaction in a frozen process, the outdated transaction is freed with kfree() directly. This skips binder_free_txn_fixups(), leaking all binder_txn_fd_fixup entries and their fget()'d struct file references. The leaked file refcounts never reach zero, so the struct file objects are permanently pinned in memory. They survive process exit and accumulate across invocations until file-max exhaustion. Every other transaction cleanup path (binder_free_transaction(), binder_transaction() error paths, binder_release_work()) correctly calls binder_free_txn_fixups(). Add the missing call before kfree() in the t_outdated cleanup block. Fixes: 9864bb480133 ("Binder: add TF_UPDATE_TXN to replace outdated txn") Cc: stable Signed-off-by: Tomer Pomeranc Acked-by: Carlos Llamas Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20260812195316.259136-2-tomerpo@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 8f2ef1bd5..f70aeb63a 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2932,6 +2932,7 @@ static int binder_proc_transaction(struct binder_transaction *t, trace_binder_transaction_update_buffer_release(buffer); binder_release_entire_buffer(proc, NULL, buffer, false); binder_alloc_free_buf(&proc->alloc, buffer); + binder_free_txn_fixups(t_outdated); kfree(t_outdated); binder_stats_deleted(BINDER_STAT_TRANSACTION); } -- cgit v1.3.1