[PATCH 5.4 132/320] binder: fix handling of error during copy

Greg Kroah-Hartman
2022-01-24T19:34:03Z

From: Todd Kjos <tkjos@google.com>

[ Upstream commit fe6b1869243f23a485a106c214bcfdc7aa0ed593 ]

If a memory copy function fails to copy the whole buffer,
a positive integar with the remaining bytes is returned.
In binder_translate_fd_array() this can result in an fd being
skipped due to the failed copy, but the loop continues
processing fds since the early return condition expects a
negative integer on error.

Fix by returning "ret > 0 ? -EINVAL : ret" to handle this case.

Fixes: bb4a2e48d510 ("binder: return errors from buffer copy functions")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20211130185152.437403-2-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 0512af0f04646..b9fb2a9269443 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2660,8 +2660,8 @@ static int binder_translate_fd_array(struct binder_fd_array_object *fda,
if (!ret)
ret = binder_translate_fd(fd, offset, t, thread,
in_reply_to);
- if (ret < 0)
- return ret;
+ if (ret)
+ return ret > 0 ? -EINVAL : ret;
}
return 0;
}
--
2.34.1