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Subject: Re: [PATCH] KEYS: encrypted: Add check for strsep
From: Mimi Zohar <zohar@linux.ibm.com>
To: Jarkko Sakkinen <jarkko@kernel.org>,
        Dan Williams
 <dan.j.williams@intel.com>,
        "Verma, Vishal L" <vishal.l.verma@intel.com>,
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Date: Thu, 01 Feb 2024 19:05:50 -0500
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On Thu, 2024-02-01 at 23:43 +0200, Jarkko Sakkinen wrote:
> On Tue Jan 30, 2024 at 8:25 PM EET, Dan Williams wrote:
> > Jarkko Sakkinen wrote:
> > > On Tue Jan 30, 2024 at 7:22 PM EET, Jarkko Sakkinen wrote:
> > > > On Wed Jan 24, 2024 at 11:10 PM EET, Verma, Vishal L wrote:
> > > > > On Wed, 2024-01-24 at 15:40 -0500, Mimi Zohar wrote:
> > > > > > On Wed, 2024-01-24 at 20:10 +0000, Verma, Vishal L wrote:
> > > > > > > Ah, thanks for confirming! Would you like me to send a
> > > > > > > revert patch or
> > > > > > > will you do it?
> > > > > > 
> > > > > > Revert "KEYS: encrypted: Add check for strsep"
> > > > > >     
> > > > > > This reverts commit
> > > > > > b4af096b5df5dd131ab796c79cedc7069d8f4882.
> > > > > >     
> > > > > > New encrypted keys are created either from kernel-generated 
> > > > > > random
> > > > > > numbers or user-provided decrypted data.  Revert the change
> > > > > > requiring
> > > > > > user-provided decrypted data.
> > > > > > 
> > > > > > 
> > > > > > Can I add your Reported-by?
> > > > > 
> > > > > Yes that works, Thank you.
> > > > 
> > > > This went totally wrong IMHO.
> > > > 
> > > > Priority should be to locate and fix the bug not revert useful
> > > > stuff
> > > > when a bug is found that has limited scope.
> > > 
> > > By guidelines here the commit is also a bug fix and reverting
> > > such commit means seeding a bug to the mainline. Also the klog
> > > message alone is a bug fix here. So also by book it really has
> > > to come back as it was already commit because we cannot
> > > knowingly mount bugs to the mainline, right?
> > 
> > No, the commit broke userspace. The rule is do not cause
> > regressions
> > even if userspace is abusing the ABI in an undesirable way. Even
> > the
> > new pr_info() is a log spamming behavior change, a pr_debug() might
> > be
> > suitable, but otherwise a logic change here needs a clear
> > description
> > about what is broken about the old userspace behavior and why the
> > kernel
> > can not possibly safely handle it.
> 
> The rationale literally gives empirical proof that the log message
> is useful by measure. It would be useless if log level is decreased
> to debug, as then sysadmin's won't take notice. I don't really know
> what is the definition of "spam" here but at least for me actually
> useful log message are not in that category.
> 
> Issue was legit but git revert is objectively an incorrect way to
> address the bug.

No, I made a mistake in upstreaming the patch in the first place.  It
broke the original "encrypted" keys usage.  Reverting it was the
correct solution.

Mimi