Messages in this thread Patch in this message | | | From | Schspa Shi <> | Subject | [PATCH v2] binder: fix atomic sleep when get extended error | Date | Wed, 18 May 2022 09:17:54 +0800 |
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binder_inner_proc_lock(thread->proc) is a spin lock, copy_to_user can't be called with in this lock.
Copy it as a local variable to fix it.
Reported-by: syzbot+46fff6434a7f968ecb39@syzkaller.appspotmail.com Fixes: bd32889e841c ("binder: add BINDER_GET_EXTENDED_ERROR ioctl") Signed-off-by: Schspa Shi <schspa@gmail.com>
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Changelog: v1 -> v2: - Remove the retry as Carlos Llamas adviced. - Use binder_set_extended_error to reset the error info. --- drivers/android/binder.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index d9253b2a7bd9..1a6b7a8c8346 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5162,19 +5162,16 @@ static int binder_ioctl_get_freezer_info( static int binder_ioctl_get_extended_error(struct binder_thread *thread, void __user *ubuf) { - struct binder_extended_error *ee = &thread->ee; + struct binder_extended_error ee; binder_inner_proc_lock(thread->proc); - if (copy_to_user(ubuf, ee, sizeof(*ee))) { - binder_inner_proc_unlock(thread->proc); - return -EFAULT; - } - - ee->id = 0; - ee->command = BR_OK; - ee->param = 0; + ee = thread->ee; + binder_set_extended_error(&thread->ee, 0, BR_OK, 0); binder_inner_proc_unlock(thread->proc); + if (copy_to_user(ubuf, &ee, sizeof(ee))) + return -EFAULT; + return 0; } -- 2.24.3 (Apple Git-128)
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