On 02/02/17 00:12, Andrew Morton wrote:
On Wed, 1 Feb 2017 19:35:40 +0530 Lokesh Vutla <[email protected]> wrote:commit 4a9d4b024a31 ("switch fput to task_work_add") implements a schedule_work() for completing fput(), but did not guarantee calling __fput() after unpacking initramfs. Because of this, there is a possibility that during boot a driver can see ETXTBSY when it tries to load a binary from initramfs as fput() is still pending on that binary. This patch makes sure that fput() is completed after unpacking initramfs and removes the call to flush_delayed_fput() in kernel_init() which happens very late after unpacking initramfs.There's not really enough info here for others to be able to decide which kernel versions need the fix. How serious is the bug? Given that it's been there for 4 years, I assume "not very"?
I think the issue only surfaces with certain timing conditions, and for some reason it has been masked for at least us until we noticed this with 4.9-lts kernel. The same issue was not detected with earlier 4.4-lts kernel.
-Tero
