[REGRESSION] stable-rc/linux-6.12.y: (build) variable 'val' is uninitialized when passed as a const pointer arg...
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.
=====================================================
# Builds where the incident occurred:
## defconfig+allmodconfig on (arm64): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-arm64-allmodconfig-6924331af5b874... - dashboard: https://d.kernelci.org/build/maestro:6924331af5b8743b1f5e538f
## defconfig+allmodconfig+CONFIG_FRAME_WARN=2048 on (arm): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-arm-allmodconfig-69243317f5b8743b... - dashboard: https://d.kernelci.org/build/maestro:69243317f5b8743b1f5e538c
## i386_defconfig+allmodconfig+CONFIG_FRAME_WARN=2048 on (i386): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-i386-allmodconfig-69243353f5b8743... - dashboard: https://d.kernelci.org/build/maestro:69243353f5b8743b1f5e53bf
## x86_64_defconfig+allmodconfig on (x86_64): - compiler: clang-21 - config: https://files.kernelci.org/kbuild-clang-21-x86-allmodconfig-69243323f5b8743b... - dashboard: https://d.kernelci.org/build/maestro:69243323f5b8743b1f5e5395
#kernelci issue maestro:5b83acc62508c670164c5fceb3079a2d7d74e154
Reported-by: kernelci.org bot bot@kernelci.org
-- This is an experimental report format. Please send feedback in! Talk to us at kernelci@lists.linux.dev
Made with love by the KernelCI team - https://kernelci.org
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/00dacf8c22f065cb52efb14cd091d441...
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
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/00dacf8c22f065cb52efb14cd091d441...
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
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/00dacf8c22f065cb52efb14cd091d441...
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
linux-stable-mirror@lists.linaro.org
-
Guenter Roeck -
KernelCI bot -
Nathan Chancellor