* Re: [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by
2023-09-22 17:53 [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by Kees Cook
@ 2023-09-22 18:05 ` Dave Jiang
2023-09-22 18:25 ` Verma, Vishal L
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Dave Jiang @ 2023-09-22 18:05 UTC (permalink / raw)
To: Kees Cook, Davidlohr Bueso
Cc: Jonathan Cameron, Alison Schofield, Vishal Verma, Ira Weiny,
Dan Williams, linux-cxl, Nathan Chancellor, Nick Desaulniers,
Tom Rix, linux-kernel, llvm, linux-hardening
On 9/22/23 10:53, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct cxl_cxims_data.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Davidlohr Bueso <dave@stgolabs.net>
> Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: linux-cxl@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
> drivers/cxl/acpi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index d1c559879dcc..40d055560e52 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -14,7 +14,7 @@
>
> struct cxl_cxims_data {
> int nr_maps;
> - u64 xormaps[];
> + u64 xormaps[] __counted_by(nr_maps);
> };
>
> /*
> @@ -112,9 +112,9 @@ static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
> GFP_KERNEL);
> if (!cximsd)
> return -ENOMEM;
> + cximsd->nr_maps = nr_maps;
> memcpy(cximsd->xormaps, cxims->xormap_list,
> nr_maps * sizeof(*cximsd->xormaps));
> - cximsd->nr_maps = nr_maps;
> cxlrd->platform_data = cximsd;
>
> return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by
2023-09-22 17:53 [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by Kees Cook
2023-09-22 18:05 ` Dave Jiang
@ 2023-09-22 18:25 ` Verma, Vishal L
2023-09-23 16:59 ` Gustavo A. R. Silva
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Verma, Vishal L @ 2023-09-22 18:25 UTC (permalink / raw)
To: keescook@chromium.org, dave@stgolabs.net
Cc: Jiang, Dave, Schofield, Alison, linux-cxl@vger.kernel.org,
jonathan.cameron@huawei.com, linux-kernel@vger.kernel.org,
Williams, Dan J, Weiny, Ira, Rix, Tom, ndesaulniers@google.com,
linux-hardening@vger.kernel.org, nathan@kernel.org,
llvm@lists.linux.dev
On Fri, 2023-09-22 at 10:53 -0700, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct cxl_cxims_data.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Davidlohr Bueso <dave@stgolabs.net>
> Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: linux-cxl@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> drivers/cxl/acpi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
>
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index d1c559879dcc..40d055560e52 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -14,7 +14,7 @@
>
> struct cxl_cxims_data {
> int nr_maps;
> - u64 xormaps[];
> + u64 xormaps[] __counted_by(nr_maps);
> };
>
> /*
> @@ -112,9 +112,9 @@ static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
> GFP_KERNEL);
> if (!cximsd)
> return -ENOMEM;
> + cximsd->nr_maps = nr_maps;
> memcpy(cximsd->xormaps, cxims->xormap_list,
> nr_maps * sizeof(*cximsd->xormaps));
> - cximsd->nr_maps = nr_maps;
> cxlrd->platform_data = cximsd;
>
> return 0;
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by
2023-09-22 17:53 [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by Kees Cook
2023-09-22 18:05 ` Dave Jiang
2023-09-22 18:25 ` Verma, Vishal L
@ 2023-09-23 16:59 ` Gustavo A. R. Silva
2023-09-28 1:18 ` Davidlohr Bueso
2023-09-28 4:48 ` Justin Stitt
4 siblings, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2023-09-23 16:59 UTC (permalink / raw)
To: Kees Cook
Cc: Davidlohr Bueso, Jonathan Cameron, Dave Jiang, Alison Schofield,
Vishal Verma, Ira Weiny, Dan Williams, linux-cxl,
Nathan Chancellor, Nick Desaulniers, Tom Rix, linux-kernel, llvm,
linux-hardening
On Fri, Sep 22, 2023 at 10:53:19AM -0700, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct cxl_cxims_data.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Davidlohr Bueso <dave@stgolabs.net>
> Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: linux-cxl@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks
--
Gustavo
> ---
> drivers/cxl/acpi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index d1c559879dcc..40d055560e52 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -14,7 +14,7 @@
>
> struct cxl_cxims_data {
> int nr_maps;
> - u64 xormaps[];
> + u64 xormaps[] __counted_by(nr_maps);
> };
>
> /*
> @@ -112,9 +112,9 @@ static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
> GFP_KERNEL);
> if (!cximsd)
> return -ENOMEM;
> + cximsd->nr_maps = nr_maps;
> memcpy(cximsd->xormaps, cxims->xormap_list,
> nr_maps * sizeof(*cximsd->xormaps));
> - cximsd->nr_maps = nr_maps;
> cxlrd->platform_data = cximsd;
>
> return 0;
> --
> 2.34.1
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by
2023-09-22 17:53 [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by Kees Cook
` (2 preceding siblings ...)
2023-09-23 16:59 ` Gustavo A. R. Silva
@ 2023-09-28 1:18 ` Davidlohr Bueso
2023-09-28 4:48 ` Justin Stitt
4 siblings, 0 replies; 6+ messages in thread
From: Davidlohr Bueso @ 2023-09-28 1:18 UTC (permalink / raw)
To: Kees Cook
Cc: Jonathan Cameron, Dave Jiang, Alison Schofield, Vishal Verma,
Ira Weiny, Dan Williams, linux-cxl, Nathan Chancellor,
Nick Desaulniers, Tom Rix, linux-kernel, llvm, linux-hardening
On Fri, 22 Sep 2023, Kees Cook wrote:
>Prepare for the coming implementation by GCC and Clang of the __counted_by
>attribute. Flexible array members annotated with __counted_by can have
>their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
>(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
>functions).
>
>As found with Coccinelle[1], add __counted_by for struct cxl_cxims_data.
>Additionally, since the element count member must be set before accessing
>the annotated flexible array member, move its initialization earlier.
Nice.
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
>
>[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
>Cc: Davidlohr Bueso <dave@stgolabs.net>
>Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
>Cc: Dave Jiang <dave.jiang@intel.com>
>Cc: Alison Schofield <alison.schofield@intel.com>
>Cc: Vishal Verma <vishal.l.verma@intel.com>
>Cc: Ira Weiny <ira.weiny@intel.com>
>Cc: Dan Williams <dan.j.williams@intel.com>
>Cc: linux-cxl@vger.kernel.org
>Signed-off-by: Kees Cook <keescook@chromium.org>
>---
> drivers/cxl/acpi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
>index d1c559879dcc..40d055560e52 100644
>--- a/drivers/cxl/acpi.c
>+++ b/drivers/cxl/acpi.c
>@@ -14,7 +14,7 @@
>
> struct cxl_cxims_data {
> int nr_maps;
>- u64 xormaps[];
>+ u64 xormaps[] __counted_by(nr_maps);
> };
>
> /*
>@@ -112,9 +112,9 @@ static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
> GFP_KERNEL);
> if (!cximsd)
> return -ENOMEM;
>+ cximsd->nr_maps = nr_maps;
> memcpy(cximsd->xormaps, cxims->xormap_list,
> nr_maps * sizeof(*cximsd->xormaps));
>- cximsd->nr_maps = nr_maps;
> cxlrd->platform_data = cximsd;
>
> return 0;
>--
>2.34.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by
2023-09-22 17:53 [PATCH] cxl/acpi: Annotate struct cxl_cxims_data with __counted_by Kees Cook
` (3 preceding siblings ...)
2023-09-28 1:18 ` Davidlohr Bueso
@ 2023-09-28 4:48 ` Justin Stitt
4 siblings, 0 replies; 6+ messages in thread
From: Justin Stitt @ 2023-09-28 4:48 UTC (permalink / raw)
To: Kees Cook
Cc: Davidlohr Bueso, Jonathan Cameron, Dave Jiang, Alison Schofield,
Vishal Verma, Ira Weiny, Dan Williams, linux-cxl,
Nathan Chancellor, Nick Desaulniers, Tom Rix, linux-kernel, llvm,
linux-hardening
On Sat, Sep 23, 2023 at 2:53 AM Kees Cook <keescook@chromium.org> wrote:
>
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct cxl_cxims_data.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Davidlohr Bueso <dave@stgolabs.net>
> Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: linux-cxl@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
Looks good.
The reordering of the count assignment is crucial here otherwise
the runtime checks will trip when `cximsd->xormaps` is used as
memcpy destination.
Reviewed-by: Justin Stitt <justinstitt@google.com>
> ---
> drivers/cxl/acpi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index d1c559879dcc..40d055560e52 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -14,7 +14,7 @@
>
> struct cxl_cxims_data {
> int nr_maps;
> - u64 xormaps[];
> + u64 xormaps[] __counted_by(nr_maps);
> };
>
> /*
> @@ -112,9 +112,9 @@ static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
> GFP_KERNEL);
> if (!cximsd)
> return -ENOMEM;
> + cximsd->nr_maps = nr_maps;
> memcpy(cximsd->xormaps, cxims->xormap_list,
> nr_maps * sizeof(*cximsd->xormaps));
> - cximsd->nr_maps = nr_maps;
> cxlrd->platform_data = cximsd;
>
> return 0;
> --
> 2.34.1
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread