From 67f6f4a6d4219ae78198880a17ab74d057449d0f Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Fri, 21 Jun 2019 10:54:15 -0700 Subject: [PATCH] binder: fix memory leak in error path commit 1909a671dbc3606685b1daf8b22a16f65ea7edda upstream. syzkallar found a 32-byte memory leak in a rarely executed error case. The transaction complete work item was not freed if put_user() failed when writing the BR_TRANSACTION_COMPLETE to the user command buffer. Fixed by freeing it before put_user() is called. Reported-by: syzbot+182ce46596c3f2e1eb24@syzkaller.appspotmail.com Signed-off-by: Todd Kjos Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 96a0f940e54d..1af9f36f89cf 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3876,6 +3876,8 @@ retry: case BINDER_WORK_TRANSACTION_COMPLETE: { binder_inner_proc_unlock(proc); cmd = BR_TRANSACTION_COMPLETE; + kfree(w); + binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); if (put_user(cmd, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); @@ -3884,8 +3886,6 @@ retry: binder_debug(BINDER_DEBUG_TRANSACTION_COMPLETE, "%d:%d BR_TRANSACTION_COMPLETE\n", proc->pid, thread->pid); - kfree(w); - binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); } break; case BINDER_WORK_NODE: { struct binder_node *node = container_of(w, struct binder_node, work); -- 2.20.1