| Message ID | 20170526164002.30103-1-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Fri, May 26, 2017 at 05:40:02PM +0100, Lorenzo Pieralisi wrote: > The BAD_MADT_GICC_ENTRY() macro checks if a GICC MADT entry passes > muster from an ACPI specification standpoint. Current macro detects the > MADT GICC entry length through ACPI firmware version (it changed from 76 > to 80 bytes in the transition from ACPI 5.1 to ACPI 6.0 specification) > but always uses (erroneously) the ACPICA (latest) struct (ie struct > acpi_madt_generic_interrupt - that is 80-bytes long) length to check if > the current GICC entry memory record exceeds the MADT table end in > memory as defined by the MADT table header itself, which may result in > false negatives depending on the ACPI firmware version and how the MADT > entries are laid out in memory (ie on ACPI 5.1 firmware MADT GICC > entries are 76 bytes long, so by adding 80 to a GICC entry start address > in memory the resulting address may well be past the actual MADT end, > triggering a false negative). > > Fix the BAD_MADT_GICC_ENTRY() macro by reshuffling the condition checks > and update them to always use the firmware version specific MADT GICC > entry length in order to carry out boundary checks. > > Fixes: b6cfb277378e ("ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro") > Reported-by: Julien Grall <julien.grall@arm.com> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Julien Grall <julien.grall@arm.com> > Cc: Hanjun Guo <hanjun.guo@linaro.org> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Al Stone <ahs3@redhat.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm64/include/asm/acpi.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) Oh, nasty: Acked-by: Will Deacon <will.deacon@arm.com> I'm assuming Catalin will pick this up as a fix. Will > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index 0e99978..59cca1d 100644 > --- a/arch/arm64/include/asm/acpi.h > +++ b/arch/arm64/include/asm/acpi.h > @@ -23,9 +23,9 @@ > #define ACPI_MADT_GICC_LENGTH \ > (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) > > -#define BAD_MADT_GICC_ENTRY(entry, end) \ > - (!(entry) || (unsigned long)(entry) + sizeof(*(entry)) > (end) || \ > - (entry)->header.length != ACPI_MADT_GICC_LENGTH) > +#define BAD_MADT_GICC_ENTRY(entry, end) \ > + (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \ > + (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end)) > > /* Basic configuration for ACPI */ > #ifdef CONFIG_ACPI > -- > 2.10.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 26/05/17 17:40, Lorenzo Pieralisi wrote: > The BAD_MADT_GICC_ENTRY() macro checks if a GICC MADT entry passes > muster from an ACPI specification standpoint. Current macro detects the > MADT GICC entry length through ACPI firmware version (it changed from 76 > to 80 bytes in the transition from ACPI 5.1 to ACPI 6.0 specification) > but always uses (erroneously) the ACPICA (latest) struct (ie struct > acpi_madt_generic_interrupt - that is 80-bytes long) length to check if > the current GICC entry memory record exceeds the MADT table end in > memory as defined by the MADT table header itself, which may result in > false negatives depending on the ACPI firmware version and how the MADT > entries are laid out in memory (ie on ACPI 5.1 firmware MADT GICC > entries are 76 bytes long, so by adding 80 to a GICC entry start address > in memory the resulting address may well be past the actual MADT end, > triggering a false negative). > > Fix the BAD_MADT_GICC_ENTRY() macro by reshuffling the condition checks > and update them to always use the firmware version specific MADT GICC > entry length in order to carry out boundary checks. > > Fixes: b6cfb277378e ("ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro") > Reported-by: Julien Grall <julien.grall@arm.com> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Julien Grall <julien.grall@arm.com> > Cc: Hanjun Guo <hanjun.guo@linaro.org> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Al Stone <ahs3@redhat.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm64/include/asm/acpi.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index 0e99978..59cca1d 100644 > --- a/arch/arm64/include/asm/acpi.h > +++ b/arch/arm64/include/asm/acpi.h > @@ -23,9 +23,9 @@ > #define ACPI_MADT_GICC_LENGTH \ > (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) > > -#define BAD_MADT_GICC_ENTRY(entry, end) \ > - (!(entry) || (unsigned long)(entry) + sizeof(*(entry)) > (end) || \ > - (entry)->header.length != ACPI_MADT_GICC_LENGTH) > +#define BAD_MADT_GICC_ENTRY(entry, end) \ > + (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \ > + (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end)) > > /* Basic configuration for ACPI */ > #ifdef CONFIG_ACPI > Acked-by: Marc Zyngier <marc.zyngier@arm.com> M.
On 05/30/2017 05:35 AM, Will Deacon wrote: > On Fri, May 26, 2017 at 05:40:02PM +0100, Lorenzo Pieralisi wrote: >> The BAD_MADT_GICC_ENTRY() macro checks if a GICC MADT entry passes >> muster from an ACPI specification standpoint. Current macro detects the >> MADT GICC entry length through ACPI firmware version (it changed from 76 >> to 80 bytes in the transition from ACPI 5.1 to ACPI 6.0 specification) >> but always uses (erroneously) the ACPICA (latest) struct (ie struct >> acpi_madt_generic_interrupt - that is 80-bytes long) length to check if >> the current GICC entry memory record exceeds the MADT table end in >> memory as defined by the MADT table header itself, which may result in >> false negatives depending on the ACPI firmware version and how the MADT >> entries are laid out in memory (ie on ACPI 5.1 firmware MADT GICC >> entries are 76 bytes long, so by adding 80 to a GICC entry start address >> in memory the resulting address may well be past the actual MADT end, >> triggering a false negative). >> >> Fix the BAD_MADT_GICC_ENTRY() macro by reshuffling the condition checks >> and update them to always use the firmware version specific MADT GICC >> entry length in order to carry out boundary checks. >> >> Fixes: b6cfb277378e ("ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro") >> Reported-by: Julien Grall <julien.grall@arm.com> >> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> >> Cc: Will Deacon <will.deacon@arm.com> >> Cc: Julien Grall <julien.grall@arm.com> >> Cc: Hanjun Guo <hanjun.guo@linaro.org> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> Cc: Al Stone <ahs3@redhat.com> >> Cc: Marc Zyngier <marc.zyngier@arm.com> >> --- >> arch/arm64/include/asm/acpi.h | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) > > Oh, nasty: > > Acked-by: Will Deacon <will.deacon@arm.com> > > I'm assuming Catalin will pick this up as a fix. > > Will Argh. Yeah, I would hope so, too, though I suspect the existing code will accidentally work much of the time. Sorry I missed this case originally. Nice catch. >> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h >> index 0e99978..59cca1d 100644 >> --- a/arch/arm64/include/asm/acpi.h >> +++ b/arch/arm64/include/asm/acpi.h >> @@ -23,9 +23,9 @@ >> #define ACPI_MADT_GICC_LENGTH \ >> (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) >> >> -#define BAD_MADT_GICC_ENTRY(entry, end) \ >> - (!(entry) || (unsigned long)(entry) + sizeof(*(entry)) > (end) || \ >> - (entry)->header.length != ACPI_MADT_GICC_LENGTH) >> +#define BAD_MADT_GICC_ENTRY(entry, end) \ >> + (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \ >> + (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end)) >> >> /* Basic configuration for ACPI */ >> #ifdef CONFIG_ACPI >> -- >> 2.10.0 >>
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 0e99978..59cca1d 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -23,9 +23,9 @@ #define ACPI_MADT_GICC_LENGTH \ (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) -#define BAD_MADT_GICC_ENTRY(entry, end) \ - (!(entry) || (unsigned long)(entry) + sizeof(*(entry)) > (end) || \ - (entry)->header.length != ACPI_MADT_GICC_LENGTH) +#define BAD_MADT_GICC_ENTRY(entry, end) \ + (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \ + (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end)) /* Basic configuration for ACPI */ #ifdef CONFIG_ACPI
The BAD_MADT_GICC_ENTRY() macro checks if a GICC MADT entry passes muster from an ACPI specification standpoint. Current macro detects the MADT GICC entry length through ACPI firmware version (it changed from 76 to 80 bytes in the transition from ACPI 5.1 to ACPI 6.0 specification) but always uses (erroneously) the ACPICA (latest) struct (ie struct acpi_madt_generic_interrupt - that is 80-bytes long) length to check if the current GICC entry memory record exceeds the MADT table end in memory as defined by the MADT table header itself, which may result in false negatives depending on the ACPI firmware version and how the MADT entries are laid out in memory (ie on ACPI 5.1 firmware MADT GICC entries are 76 bytes long, so by adding 80 to a GICC entry start address in memory the resulting address may well be past the actual MADT end, triggering a false negative). Fix the BAD_MADT_GICC_ENTRY() macro by reshuffling the condition checks and update them to always use the firmware version specific MADT GICC entry length in order to carry out boundary checks. Fixes: b6cfb277378e ("ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro") Reported-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Julien Grall <julien.grall@arm.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Al Stone <ahs3@redhat.com> Cc: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm64/include/asm/acpi.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)