[lkml]   [2017]   [Nov]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: d7be102f29 ("cfg80211: initialize regulatory keys/database later"): kernel BUG at crypto/asymmetric_keys/public_key.c:80!
On Mon, Nov 27, 2017 at 3:25 PM, David Howells <> wrote:
> Linus Torvalds <> wrote:
>> I'm not seeing why it would ever be ok to do BUG_ON() instead of just
>> returning an error, though.
> This function has a list of requisite parameters for the caller:
> BUG_ON(!pkey); <-- You need the public key to use,
> BUG_ON(!sig);
> BUG_ON(!sig->digest); <-- the message digest to check
> BUG_ON(!sig->s); <-- and you need the signature.
> If you fail to obtain any one of these parameters, you can't use this function
> and you should have errored out before calling this function. It seems
> reasonable for the function to assume that you've provided them - they're kind
> of essential to the operation. If you want, I can just remove the checks
> entirely. Many of the kernel's functions don't perform argument checking, but
> just assume you've done it right and will oops if you haven't.
> I could just return -EINVAL, yes, but I'm not sure that's really the right
> thing to do, at least not without printing an error message, since it's a
> kernel programming error not a userspace error or data error.

The preference even in these cases has been to keep things recoverable
unless there is a very good reason to immediately stop the kernel's
thread of execution. If all callers already check for return values,
replacing BUG_ON() with WARN() and returning -EINVAL would be best.


Kees Cook
Pixel Security

 \ /
  Last update: 2017-11-28 00:31    [W:0.096 / U:0.404 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site