Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

[Nathan Chancellor]

On Mon, Nov 24, 2025 at 12:59:08PM -0000, KernelCI bot wrote:
> Hello,
> 
> New build issue found on stable-rc/linux-6.12.y:
> 
> ---
>  variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] in drivers/staging/rtl8712/rtl8712_cmd.o (drivers/staging/rtl8712/rtl8712_cmd.c) [logspec:kbuild,kbuild.compiler.error]
> ---
> 
> - dashboard: https://d.kernelci.org/i/maestro:5b83acc62508c670164c5fceb3079a2d7d74e154
> - giturl: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> - commit HEAD:  d5dc97879a97b328a89ec092271faa3db9f2bff3
> - tags: v6.12.59
> 
> 
> Log excerpt:
> =====================================================
> drivers/staging/rtl8712/rtl8712_cmd.c:148:28: error: variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
>   148 |                 memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);
>       |                                          ^~~
> 1 error generated.

This comes from a new subwarning of -Wuninitialized introduced in
clang-21:

  https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441f19b319e

This driver was removed upstream in commit 41e883c137eb ("staging:
rtl8712: Remove driver using deprecated API wext") in 6.13 so this only
impacts stable.

This certainly does look broken...

  static u8 read_rfreg_hdl(struct _adapter *padapter, u8 *pbuf)
  {
      u32 val;
      void (*pcmd_callback)(struct _adapter *dev, struct cmd_obj *pcmd);
      struct cmd_obj *pcmd  = (struct cmd_obj *)pbuf;

      if (pcmd->rsp && pcmd->rspsz > 0)
          memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);

Presumably this is never actually hit? It is rather hard to follow the
indirection in this driver but it does not seem like _Read_RFREG is ever
set as a cmdcode? Unfortunately, the only maintainer I see listed for
this file is Florian Schilhabel but a glance at lore shows no recent
activity so that probably won't be too much help. At the very least, we
could just zero initialize val, it cannot be any worse than what it is
currently doing and copying stack garbage?

Cheers,
Nathan

Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

[Guenter Roeck]

On Mon, Nov 24, 2025 at 2:04 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> On Mon, Nov 24, 2025 at 12:59:08PM -0000, KernelCI bot wrote:
> > Hello,
> >
> > New build issue found on stable-rc/linux-6.12.y:
> >
> > ---
> >  variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] in drivers/staging/rtl8712/rtl8712_cmd.o (drivers/staging/rtl8712/rtl8712_cmd.c) [logspec:kbuild,kbuild.compiler.error]
> > ---
> >
> > - dashboard: https://d.kernelci.org/i/maestro:5b83acc62508c670164c5fceb3079a2d7d74e154
> > - giturl: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> > - commit HEAD:  d5dc97879a97b328a89ec092271faa3db9f2bff3
> > - tags: v6.12.59
> >
> >
> > Log excerpt:
> > =====================================================
> > drivers/staging/rtl8712/rtl8712_cmd.c:148:28: error: variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
> >   148 |                 memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);
> >       |                                          ^~~
> > 1 error generated.
>
> This comes from a new subwarning of -Wuninitialized introduced in
> clang-21:
>
>   https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441f19b319e
>
> This driver was removed upstream in commit 41e883c137eb ("staging:
> rtl8712: Remove driver using deprecated API wext") in 6.13 so this only
> impacts stable.
>
> This certainly does look broken...
>
>   static u8 read_rfreg_hdl(struct _adapter *padapter, u8 *pbuf)
>   {
>       u32 val;
>       void (*pcmd_callback)(struct _adapter *dev, struct cmd_obj *pcmd);
>       struct cmd_obj *pcmd  = (struct cmd_obj *)pbuf;
>
>       if (pcmd->rsp && pcmd->rspsz > 0)
>           memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);
>
> Presumably this is never actually hit? It is rather hard to follow the
> indirection in this driver but it does not seem like _Read_RFREG is ever
> set as a cmdcode? Unfortunately, the only maintainer I see listed for
> this file is Florian Schilhabel but a glance at lore shows no recent
> activity so that probably won't be too much help. At the very least, we
> could just zero initialize val, it cannot be any worse than what it is
> currently doing and copying stack garbage?
>

Or backport the patch removing the driver ? It is in staging, after
all, so I don't know if there is value in trying to keep it alive in
6.12.y.

Guenter

> Cheers,
> Nathan
>

Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

[Nathan Chancellor]

On Mon, Nov 24, 2025 at 02:35:26PM -0800, Guenter Roeck wrote:
> On Mon, Nov 24, 2025 at 2:04 PM Nathan Chancellor <nathan@kernel.org> wrote:
> >
> > On Mon, Nov 24, 2025 at 12:59:08PM -0000, KernelCI bot wrote:
> > > Hello,
> > >
> > > New build issue found on stable-rc/linux-6.12.y:
> > >
> > > ---
> > >  variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] in drivers/staging/rtl8712/rtl8712_cmd.o (drivers/staging/rtl8712/rtl8712_cmd.c) [logspec:kbuild,kbuild.compiler.error]
> > > ---
> > >
> > > - dashboard: https://d.kernelci.org/i/maestro:5b83acc62508c670164c5fceb3079a2d7d74e154
> > > - giturl: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> > > - commit HEAD:  d5dc97879a97b328a89ec092271faa3db9f2bff3
> > > - tags: v6.12.59
> > >
> > >
> > > Log excerpt:
> > > =====================================================
> > > drivers/staging/rtl8712/rtl8712_cmd.c:148:28: error: variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
> > >   148 |                 memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);
> > >       |                                          ^~~
> > > 1 error generated.
> >
> > This comes from a new subwarning of -Wuninitialized introduced in
> > clang-21:
> >
> >   https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441f19b319e
> >
> > This driver was removed upstream in commit 41e883c137eb ("staging:
> > rtl8712: Remove driver using deprecated API wext") in 6.13 so this only
> > impacts stable.
> >
> > This certainly does look broken...
> >
> >   static u8 read_rfreg_hdl(struct _adapter *padapter, u8 *pbuf)
> >   {
> >       u32 val;
> >       void (*pcmd_callback)(struct _adapter *dev, struct cmd_obj *pcmd);
> >       struct cmd_obj *pcmd  = (struct cmd_obj *)pbuf;
> >
> >       if (pcmd->rsp && pcmd->rspsz > 0)
> >           memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);
> >
> > Presumably this is never actually hit? It is rather hard to follow the
> > indirection in this driver but it does not seem like _Read_RFREG is ever
> > set as a cmdcode? Unfortunately, the only maintainer I see listed for
> > this file is Florian Schilhabel but a glance at lore shows no recent
> > activity so that probably won't be too much help. At the very least, we
> > could just zero initialize val, it cannot be any worse than what it is
> > currently doing and copying stack garbage?
> >
> 
> Or backport the patch removing the driver ? It is in staging, after
> all, so I don't know if there is value in trying to keep it alive in
> 6.12.y.

That would likely not be the end of the world for 6.12.y but this
warning appears all the way back to at least 5.15 (the point I start
caring about warnings because of CONFIG_WERROR).

Cheers,
Nathan

Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

[Greg Kroah-Hartman]

On Mon, Nov 24, 2025 at 03:40:46PM -0700, Nathan Chancellor wrote:
> On Mon, Nov 24, 2025 at 02:35:26PM -0800, Guenter Roeck wrote:
> > On Mon, Nov 24, 2025 at 2:04 PM Nathan Chancellor <nathan@kernel.org> wrote:
> > >
> > > On Mon, Nov 24, 2025 at 12:59:08PM -0000, KernelCI bot wrote:
> > > > Hello,
> > > >
> > > > New build issue found on stable-rc/linux-6.12.y:
> > > >
> > > > ---
> > > >  variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] in drivers/staging/rtl8712/rtl8712_cmd.o (drivers/staging/rtl8712/rtl8712_cmd.c) [logspec:kbuild,kbuild.compiler.error]
> > > > ---
> > > >
> > > > - dashboard: https://d.kernelci.org/i/maestro:5b83acc62508c670164c5fceb3079a2d7d74e154
> > > > - giturl: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> > > > - commit HEAD:  d5dc97879a97b328a89ec092271faa3db9f2bff3
> > > > - tags: v6.12.59
> > > >
> > > >
> > > > Log excerpt:
> > > > =====================================================
> > > > drivers/staging/rtl8712/rtl8712_cmd.c:148:28: error: variable 'val' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
> > > >   148 |                 memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);
> > > >       |                                          ^~~
> > > > 1 error generated.
> > >
> > > This comes from a new subwarning of -Wuninitialized introduced in
> > > clang-21:
> > >
> > >   https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441f19b319e
> > >
> > > This driver was removed upstream in commit 41e883c137eb ("staging:
> > > rtl8712: Remove driver using deprecated API wext") in 6.13 so this only
> > > impacts stable.
> > >
> > > This certainly does look broken...
> > >
> > >   static u8 read_rfreg_hdl(struct _adapter *padapter, u8 *pbuf)
> > >   {
> > >       u32 val;
> > >       void (*pcmd_callback)(struct _adapter *dev, struct cmd_obj *pcmd);
> > >       struct cmd_obj *pcmd  = (struct cmd_obj *)pbuf;
> > >
> > >       if (pcmd->rsp && pcmd->rspsz > 0)
> > >           memcpy(pcmd->rsp, (u8 *)&val, pcmd->rspsz);
> > >
> > > Presumably this is never actually hit? It is rather hard to follow the
> > > indirection in this driver but it does not seem like _Read_RFREG is ever
> > > set as a cmdcode? Unfortunately, the only maintainer I see listed for
> > > this file is Florian Schilhabel but a glance at lore shows no recent
> > > activity so that probably won't be too much help. At the very least, we
> > > could just zero initialize val, it cannot be any worse than what it is
> > > currently doing and copying stack garbage?
> > >
> > 
> > Or backport the patch removing the driver ? It is in staging, after
> > all, so I don't know if there is value in trying to keep it alive in
> > 6.12.y.
> 
> That would likely not be the end of the world for 6.12.y but this
> warning appears all the way back to at least 5.15 (the point I start
> caring about warnings because of CONFIG_WERROR).

No objection from me to delete the driver from all of the stable trees :)

thanks,

greg k-h

Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

[Nathan Chancellor]

On Thu, Nov 27, 2025 at 02:22:46PM +0100, Greg Kroah-Hartman wrote:
> No objection from me to delete the driver from all of the stable trees :)

Sounds rather nuclear for the issue at hand :) but I can send the
backports for that change and we can see who complains before trying a
more localized (even if wrong) fix.

Cheers,
Nathan

Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

[Guenter Roeck]

On Wed, Dec 3, 2025 at 4:43 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> On Thu, Nov 27, 2025 at 02:22:46PM +0100, Greg Kroah-Hartman wrote:
> > No objection from me to delete the driver from all of the stable trees :)
>
> Sounds rather nuclear for the issue at hand :) but I can send the
> backports for that change and we can see who complains before trying a
> more localized (even if wrong) fix.
>

Already done (and queued for the next stable releases). Sorry, I
wanted to copy you but ended up copying myself.

Guenter

Re: [REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...

[Nathan Chancellor]

On Wed, Dec 03, 2025 at 05:03:24PM -0800, Guenter Roeck wrote:
> On Wed, Dec 3, 2025 at 4:43 PM Nathan Chancellor <nathan@kernel.org> wrote:
> >
> > On Thu, Nov 27, 2025 at 02:22:46PM +0100, Greg Kroah-Hartman wrote:
> > > No objection from me to delete the driver from all of the stable trees :)
> >
> > Sounds rather nuclear for the issue at hand :) but I can send the
> > backports for that change and we can see who complains before trying a
> > more localized (even if wrong) fix.
> >
> 
> Already done (and queued for the next stable releases). Sorry, I
> wanted to copy you but ended up copying myself.

Ah great, one less thing for me to do :)

Cheers,
Nathan