Re: [PATCH] ceph: Move a variable assignment behind a condition check in __ceph_remove_cap()

[Dan Carpenter]

On Mon, Jul 13, 2026 at 03:10:40PM -0700, Viacheslav Dubeyko wrote:
> On Mon, 2026-07-13 at 13:35 +0200, Markus Elfring wrote:
> > From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > Date: Mon, 13 Jul 2026 13:21:29 +0200
> > 
> > The address of a data structure member was determined before
> > a corresponding null pointer check in the implementation of
> > the function “__ceph_remove_cap”.
> > 
> > Thus avoid the risk for undefined behaviour by moving the assignment
> > for the variable “inode” behind a condition check.
> > 
> > This issue was detected by using the Coccinelle software.
> > 
> > Fixes: 38d46409c4639a1d659ebfa70e27a8bed6b8ee1d ("ceph: print cluster
> > fsid and client global_id in all debug logs")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>

I have explained to Markus many times that these are not dereferences,
they are just pointer math.  So the original code works fine and does
not need a Fixes tag or a CC to stable.

And then Markus responds, "the C standard says we are not allowed to
dereference NULL pointers"...  Which is true, but again, it's not a
dereference.

regards,
dan carpenter