| Message ID | 20231128025411.141602-1-dmantipov@yandex.ru (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | [v2] pnp: acpi: fix fortify warning | expand |
On Tue, Nov 28, 2023 at 05:52:10AM +0300, Dmitry Antipov wrote: > When compiling with gcc version 14.0.0 20231126 (experimental) > and CONFIG_FORTIFY_SOURCE=y, I've noticed the following: > > In file included from ./include/linux/string.h:295, > from ./include/linux/bitmap.h:12, > from ./include/linux/cpumask.h:12, > from ./arch/x86/include/asm/paravirt.h:17, > from ./arch/x86/include/asm/cpuid.h:62, > from ./arch/x86/include/asm/processor.h:19, > from ./arch/x86/include/asm/cpufeature.h:5, > from ./arch/x86/include/asm/thread_info.h:53, > from ./include/linux/thread_info.h:60, > from ./arch/x86/include/asm/preempt.h:9, > from ./include/linux/preempt.h:79, > from ./include/linux/spinlock.h:56, > from ./include/linux/mmzone.h:8, > from ./include/linux/gfp.h:7, > from ./include/linux/slab.h:16, > from ./include/linux/resource_ext.h:11, > from ./include/linux/acpi.h:13, > from drivers/pnp/pnpacpi/rsparser.c:11: > In function 'fortify_memcpy_chk', > inlined from 'pnpacpi_parse_allocated_vendor' at drivers/pnp/pnpacpi/rsparser.c:158:3, > inlined from 'pnpacpi_allocated_resource' at drivers/pnp/pnpacpi/rsparser.c:249:3: > ./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field' > declared with attribute warning: detected read beyond size of field (2nd parameter); > maybe use struct_group()? [-Wattribute-warning] > 588 | __read_overflow2_field(q_size_field, size); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > According to the comments in include/linux/fortify-string.h, 'memcpy()', > 'memmove()' and 'memset()' must not be used beyond individual struct > members to ensure that the compiler can enforce protection against > buffer overflows, and, IIUC, this also applies to partial copies from > the particular member ('vendor->byte_data' in this case). So it should > be better (and safer) to do both copies at once (and 'byte_data' of > 'struct acpi_resource_vendor_typed' seems to be a good candidate for > '__counted_by(byte_length)' as well). > > Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> > --- > v2: prefer sizeof(range) over hardcoded constant (Rafael J. Wysocki) Yeah, this looks good to me. Thanks for the fix! Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > drivers/pnp/pnpacpi/rsparser.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c > index 4f05f610391b..c02ce0834c2c 100644 > --- a/drivers/pnp/pnpacpi/rsparser.c > +++ b/drivers/pnp/pnpacpi/rsparser.c > @@ -151,13 +151,13 @@ static int vendor_resource_matches(struct pnp_dev *dev, > static void pnpacpi_parse_allocated_vendor(struct pnp_dev *dev, > struct acpi_resource_vendor_typed *vendor) > { > - if (vendor_resource_matches(dev, vendor, &hp_ccsr_uuid, 16)) { > - u64 start, length; > + struct { u64 start, length; } range; > > - memcpy(&start, vendor->byte_data, sizeof(start)); > - memcpy(&length, vendor->byte_data + 8, sizeof(length)); > - > - pnp_add_mem_resource(dev, start, start + length - 1, 0); > + if (vendor_resource_matches(dev, vendor, &hp_ccsr_uuid, > + sizeof(range))) { > + memcpy(&range, vendor->byte_data, sizeof(range)); > + pnp_add_mem_resource(dev, range.start, range.start + > + range.length - 1, 0); > } > } > > -- > 2.43.0 >
On Fri, Dec 1, 2023 at 12:29 AM Kees Cook <keescook@chromium.org> wrote: > > On Tue, Nov 28, 2023 at 05:52:10AM +0300, Dmitry Antipov wrote: > > When compiling with gcc version 14.0.0 20231126 (experimental) > > and CONFIG_FORTIFY_SOURCE=y, I've noticed the following: > > > > In file included from ./include/linux/string.h:295, > > from ./include/linux/bitmap.h:12, > > from ./include/linux/cpumask.h:12, > > from ./arch/x86/include/asm/paravirt.h:17, > > from ./arch/x86/include/asm/cpuid.h:62, > > from ./arch/x86/include/asm/processor.h:19, > > from ./arch/x86/include/asm/cpufeature.h:5, > > from ./arch/x86/include/asm/thread_info.h:53, > > from ./include/linux/thread_info.h:60, > > from ./arch/x86/include/asm/preempt.h:9, > > from ./include/linux/preempt.h:79, > > from ./include/linux/spinlock.h:56, > > from ./include/linux/mmzone.h:8, > > from ./include/linux/gfp.h:7, > > from ./include/linux/slab.h:16, > > from ./include/linux/resource_ext.h:11, > > from ./include/linux/acpi.h:13, > > from drivers/pnp/pnpacpi/rsparser.c:11: > > In function 'fortify_memcpy_chk', > > inlined from 'pnpacpi_parse_allocated_vendor' at drivers/pnp/pnpacpi/rsparser.c:158:3, > > inlined from 'pnpacpi_allocated_resource' at drivers/pnp/pnpacpi/rsparser.c:249:3: > > ./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field' > > declared with attribute warning: detected read beyond size of field (2nd parameter); > > maybe use struct_group()? [-Wattribute-warning] > > 588 | __read_overflow2_field(q_size_field, size); > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > According to the comments in include/linux/fortify-string.h, 'memcpy()', > > 'memmove()' and 'memset()' must not be used beyond individual struct > > members to ensure that the compiler can enforce protection against > > buffer overflows, and, IIUC, this also applies to partial copies from > > the particular member ('vendor->byte_data' in this case). So it should > > be better (and safer) to do both copies at once (and 'byte_data' of > > 'struct acpi_resource_vendor_typed' seems to be a good candidate for > > '__counted_by(byte_length)' as well). > > > > Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> > > --- > > v2: prefer sizeof(range) over hardcoded constant (Rafael J. Wysocki) > > Yeah, this looks good to me. Thanks for the fix! > > Reviewed-by: Kees Cook <keescook@chromium.org> Applied as 6.8 material, thanks!
diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c index 4f05f610391b..c02ce0834c2c 100644 --- a/drivers/pnp/pnpacpi/rsparser.c +++ b/drivers/pnp/pnpacpi/rsparser.c @@ -151,13 +151,13 @@ static int vendor_resource_matches(struct pnp_dev *dev, static void pnpacpi_parse_allocated_vendor(struct pnp_dev *dev, struct acpi_resource_vendor_typed *vendor) { - if (vendor_resource_matches(dev, vendor, &hp_ccsr_uuid, 16)) { - u64 start, length; + struct { u64 start, length; } range; - memcpy(&start, vendor->byte_data, sizeof(start)); - memcpy(&length, vendor->byte_data + 8, sizeof(length)); - - pnp_add_mem_resource(dev, start, start + length - 1, 0); + if (vendor_resource_matches(dev, vendor, &hp_ccsr_uuid, + sizeof(range))) { + memcpy(&range, vendor->byte_data, sizeof(range)); + pnp_add_mem_resource(dev, range.start, range.start + + range.length - 1, 0); } }
When compiling with gcc version 14.0.0 20231126 (experimental) and CONFIG_FORTIFY_SOURCE=y, I've noticed the following: In file included from ./include/linux/string.h:295, from ./include/linux/bitmap.h:12, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/paravirt.h:17, from ./arch/x86/include/asm/cpuid.h:62, from ./arch/x86/include/asm/processor.h:19, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:9, from ./include/linux/preempt.h:79, from ./include/linux/spinlock.h:56, from ./include/linux/mmzone.h:8, from ./include/linux/gfp.h:7, from ./include/linux/slab.h:16, from ./include/linux/resource_ext.h:11, from ./include/linux/acpi.h:13, from drivers/pnp/pnpacpi/rsparser.c:11: In function 'fortify_memcpy_chk', inlined from 'pnpacpi_parse_allocated_vendor' at drivers/pnp/pnpacpi/rsparser.c:158:3, inlined from 'pnpacpi_allocated_resource' at drivers/pnp/pnpacpi/rsparser.c:249:3: ./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 588 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ According to the comments in include/linux/fortify-string.h, 'memcpy()', 'memmove()' and 'memset()' must not be used beyond individual struct members to ensure that the compiler can enforce protection against buffer overflows, and, IIUC, this also applies to partial copies from the particular member ('vendor->byte_data' in this case). So it should be better (and safer) to do both copies at once (and 'byte_data' of 'struct acpi_resource_vendor_typed' seems to be a good candidate for '__counted_by(byte_length)' as well). Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> --- v2: prefer sizeof(range) over hardcoded constant (Rafael J. Wysocki) --- drivers/pnp/pnpacpi/rsparser.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)