bf88fef0b6
The HNP work can be re-scheduled while it's still in-fly. This results in re-initialization of the busy work, resetting the hrtimer's list node of the work and crashing kernel with null dereference within kernel/timer once work's timer is expired. It's very easy to trigger this problem by re-plugging USB cable quickly. Initialize HNP work only once to fix this trouble. Unable to handle kernel NULL pointer dereference at virtual address 00000126) ... PC is at __run_timers.part.0+0x150/0x228 LR is at __next_timer_interrupt+0x51/0x9c ... (__run_timers.part.0) from [<c0187a2b>] (run_timer_softirq+0x2f/0x50) (run_timer_softirq) from [<c01013ad>] (__do_softirq+0xd5/0x2f0) (__do_softirq) from [<c012589b>] (irq_exit+0xab/0xb8) (irq_exit) from [<c0170341>] (handle_domain_irq+0x45/0x60) (handle_domain_irq) from [<c04c4a43>] (gic_handle_irq+0x6b/0x7c) (gic_handle_irq) from [<c0100b65>] (__irq_svc+0x65/0xac) Cc: stable@vger.kernel.org Acked-by: Peter Chen <peter.chen@kernel.org> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Link: https://lore.kernel.org/r/20210717182134.30262-6-digetx@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.