From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH] serial: 8250: Fix serial8250 initialization crash Date: Fri, 18 Jan 2019 13:02:53 +0100 Message-ID: <20190118120253.GB5532@kroah.com> References: <1547715619-181299-1-git-send-email-zhe.he@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1547715619-181299-1-git-send-email-zhe.he@windriver.com> Sender: linux-kernel-owner@vger.kernel.org To: zhe.he@windriver.com Cc: jslaby@suse.com, andriy.shevchenko@linux.intel.com, bigeasy@linutronix.de, Jisheng.Zhang@synaptics.com, darwin.dingel@alliedtelesis.co.nz, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-serial@vger.kernel.org On Thu, Jan 17, 2019 at 05:00:19PM +0800, zhe.he@windriver.com wrote: > From: He Zhe > > The initialization code of interrupt backoff work might reference NULL > pointer and cause the following crash, if no port was found. > > [ 10.017727] CPU 0 Unable to handle kernel paging request at virtual address 000001b0, epc == 807088e0, ra == 8070863c > ---- snip ---- > [ 11.704470] [<807088e0>] serial8250_register_8250_port+0x318/0x4ac > [ 11.747251] [<80708d74>] serial8250_probe+0x148/0x1c0 > [ 11.789301] [<80728450>] platform_drv_probe+0x40/0x94 > [ 11.830515] [<807264f8>] really_probe+0xf8/0x318 > [ 11.870876] [<80726b7c>] __driver_attach+0x110/0x12c > [ 11.910960] [<80724374>] bus_for_each_dev+0x78/0xcc > [ 11.951134] [<80725958>] bus_add_driver+0x200/0x234 > [ 11.989756] [<807273d8>] driver_register+0x84/0x148 > [ 12.029832] [<80d72f84>] serial8250_init+0x138/0x198 > [ 12.070447] [<80100e6c>] do_one_initcall+0x5c/0x2a0 > [ 12.110104] [<80d3a208>] kernel_init_freeable+0x370/0x484 > [ 12.150722] [<80a49420>] kernel_init+0x10/0xf8 > [ 12.191517] [<8010756c>] ret_from_kernel_thread+0x14/0x1c > > This patch makes sure the initialization code can be reached only if a port > is found. > > Fixes: commit 6d7f677a2afa ("serial: 8250: Rate limit serial port rx interrupts during input overruns") No need for the "commit" in this string, this can just be written as: Fixes: 6d7f677a2afa ("serial: 8250: Rate limit serial port rx interrupts during input overruns") thanks, greg k-h