Re: net/xfrm/xfrm_policy.c:1286:8: error: variable 'dir' is uninitialized when used here [-Werror,-Wuninitialized]

[Simon Horman <horms@kernel.org>]

On Fri, Aug 30, 2024 at 02:47:57PM -0700, Nathan Chancellor wrote:
> Hi Simon (and Naresh),
> 
> On Fri, Aug 30, 2024 at 06:04:49PM +0100, Simon Horman wrote:
> > On Fri, Aug 30, 2024 at 05:47:06PM +0100, Simon Horman wrote:
> > > + Florian, Steffen
> > > 
> > > On Fri, Aug 30, 2024 at 12:15:10PM +0530, Naresh Kamboju wrote:
> > > > The x86_64 defconfig builds failed on today's Linux next-20240829
> > > > due to following build warnings / errors.
> > > > 
> > > > Regressions:
> > > > * i386, build
> > > >   - clang-18-defconfig
> > > >   - clang-nightly-defconfig
> > > > 
> > > > * x86_64, build
> > > >   - clang-18-lkftconfig
> > > >   - clang-18-lkftconfig-compat
> > > >   - clang-18-lkftconfig-kcsan
> > > >   - clang-18-lkftconfig-no-kselftest-frag
> > > >   - clang-18-x86_64_defconfig
> > > >   - clang-nightly-lkftconfig
> > > >   - clang-nightly-lkftconfig-kselftest
> > > >   - clang-nightly-x86_64_defconfig
> > > >   - rustclang-nightly-lkftconfig-kselftest
> > > > 
> > > > first seen on next-20240829.
> > > >   Good: next-20240828
> > > >   BAD:  next-20240829
> > > > 
> > > > Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
> > > > 
> > > > build log:
> > > > --------
> > > > net/xfrm/xfrm_policy.c:1286:8: error: variable 'dir' is uninitialized
> > > > when used here [-Werror,-Wuninitialized]
> > > >  1286 |                 if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
> > > >       |                      ^~~
> > > > net/xfrm/xfrm_policy.c:1257:9: note: initialize the variable 'dir' to
> > > > silence this warning
> > > >  1257 |         int dir;
> > > >       |                ^
> > > >       |                 = 0
> > > > 1 error generated.
> 
> Thanks for the report.
> 
> > > I believe that is due to
> > > commit 08c2182cf0b4 ("xfrm: policy: use recently added helper in more places")
> > > 
> > > I will work on a fix to initialise dir in the loop where it is used.
> > 
> > Patch is here:
> > - [PATCH ipsec-next] xfrm: Initialise dir in xfrm_hash_rebuild()
> >   https://lore.kernel.org/netdev/20240830-xfrm_hash_rebuild-dir-v1-1-f75092d07e1b@kernel.org/T/#u
> 
> I sent the same patch as a v1 but Florian pointed out that dir needs to
> be initialized in the other loop too. I sent my v2 for it yesterday, it
> just needs to be merged.
> 
> https://lore.kernel.org/all/20240829-xfrm-restore-dir-assign-xfrm_hash_rebuild-v2-1-1cf8958f6e8e@kernel.org/

Thanks, and sorry for the noise.