Messages in this thread | | | Subject | Re: [PATCH v6 2/7] fpga: sec-mgr: enable secure updates | From | Martin Hundebøll <> | Date | Wed, 2 Dec 2020 14:40:53 +0100 |
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Hi Russ,
On 02/12/2020 00.30, Russ Weight wrote: > > On 12/1/20 12:47 AM, Martin Hundebøll wrote: >> Hi Russ, >> >> On 01/12/2020 00.54, Russ Weight wrote: >>> Thanks Martin. I'll work on a fix for this. >> Attached is my in-house fix. >> >> // Martin >> >>> On 11/26/20 6:02 AM, Martin Hundebøll wrote: >>>> Hi Russ, >>>> >>>> I found another thing while testing this... >>>> >>>> On 06/11/2020 02.09, Russ Weight wrote: >>>> >>>> <snip> >>>> >>>>> +static ssize_t filename_store(struct device *dev, struct device_attribute *attr, >>>>> + const char *buf, size_t count) >>>>> +{ >>>>> + struct fpga_sec_mgr *smgr = to_sec_mgr(dev); >>>>> + int ret = count; >>>>> + >>>>> + if (count == 0 || count >= PATH_MAX) >>>>> + return -EINVAL; >>>>> + >>>>> + mutex_lock(&smgr->lock); >>>>> + if (smgr->driver_unload || smgr->progress != FPGA_SEC_PROG_IDLE) { >>>>> + ret = -EBUSY; >>>>> + goto unlock_exit; >>>>> + } >>>>> + >>>>> + smgr->filename = kstrndup(buf, count - 1, GFP_KERNEL); >>>> The `count - 1` is meant to remove a trailing newline, but opae-sdk writes the filename without newline, so better do it conditionally... > After looking at how kstrndup() is used elsewhere, and after > doing some experimentation, I think the best fix may be to just > remove the "- 1": > > smgr->filename = kstrndup(buf, count, GFP_KERNEL); > > The code shouldn't have assumed a "\n", and I don't think the > kernel should be required to do white-space cleanup. > > Does this fix seem OK to you?
Since we always use opae-sdk to write the filename, we wouldn't even notice.
While your'e at it, kerneldoc in mm/util.c suggests to use kmemdup_nul() when the size is known.
// Martin
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