2018-08-27 19:21:38

by David Arcari

Subject: [PATCH] mailbox: PCC: handle parse error

acpi_pcc_probe calls acpi_table_parse_entries_array but fails to check
for an error return. This in turn can result in calling kcalloc with
a negative count as well as emitting the following misleading erorr
message:

[ 2.642015] Could not allocate space for PCC mbox channels

Fixes: 8f8027c5f935 ("mailbox: PCC: erroneous error message when parsing ACPI PCCT")

Signed-off-by: David Arcari <[email protected]>
Cc: Al Stone <[email protected]>
Cc: Jassi Brar <[email protected]>
---
drivers/mailbox/pcc.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 311e91b..256f18b 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -461,8 +461,11 @@ static int __init acpi_pcc_probe(void)
count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
sizeof(struct acpi_table_pcct), proc,
ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
- if (count == 0 || count > MAX_PCC_SUBSPACES) {
- pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
+ if (count <= 0 || count > MAX_PCC_SUBSPACES) {
+ if (count < 0)
+ pr_warn("Error parsing PCC subspaces from PCCT\n");
+ else
+ pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
return -EINVAL;
}

--
1.8.3.1

2018-08-27 20:57:46

by Al Stone

Subject: Re: [PATCH] mailbox: PCC: handle parse error

On 08/27/2018 01:19 PM, David Arcari wrote:
> acpi_pcc_probe calls acpi_table_parse_entries_array but fails to check
> for an error return. This in turn can result in calling kcalloc with
> a negative count as well as emitting the following misleading erorr
> message:
>
> [ 2.642015] Could not allocate space for PCC mbox channels
>
> Fixes: 8f8027c5f935 ("mailbox: PCC: erroneous error message when parsing ACPI PCCT")
>
> Signed-off-by: David Arcari <[email protected]>
> Cc: Al Stone <[email protected]>
> Cc: Jassi Brar <[email protected]>
> ---
> drivers/mailbox/pcc.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
> index 311e91b..256f18b 100644
> --- a/drivers/mailbox/pcc.c
> +++ b/drivers/mailbox/pcc.c
> @@ -461,8 +461,11 @@ static int __init acpi_pcc_probe(void)
> count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
> sizeof(struct acpi_table_pcct), proc,
> ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
> - if (count == 0 || count > MAX_PCC_SUBSPACES) {
> - pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
> + if (count <= 0 || count > MAX_PCC_SUBSPACES) {
> + if (count < 0)
> + pr_warn("Error parsing PCC subspaces from PCCT\n");
> + else
> + pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
> return -EINVAL;
> }
>
>

Thanks, David. Nice catch.

Reviewed-by: Al Stone <[email protected]>

--
ciao,
al
-----------------------------------
Al Stone
Software Engineer
Red Hat, Inc.
[email protected]
-----------------------------------

2018-09-14 08:44:57

by Rafael J. Wysocki

Subject: Re: [PATCH] mailbox: PCC: handle parse error

On Monday, August 27, 2018 10:55:41 PM CEST Al Stone wrote:
> On 08/27/2018 01:19 PM, David Arcari wrote:
> > acpi_pcc_probe calls acpi_table_parse_entries_array but fails to check
> > for an error return. This in turn can result in calling kcalloc with
> > a negative count as well as emitting the following misleading erorr
> > message:
> >
> > [ 2.642015] Could not allocate space for PCC mbox channels
> >
> > Fixes: 8f8027c5f935 ("mailbox: PCC: erroneous error message when parsing ACPI PCCT")
> >
> > Signed-off-by: David Arcari <[email protected]>
> > Cc: Al Stone <[email protected]>
> > Cc: Jassi Brar <[email protected]>
> > ---
> > drivers/mailbox/pcc.c | 7 +++++--
> > 1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
> > index 311e91b..256f18b 100644
> > --- a/drivers/mailbox/pcc.c
> > +++ b/drivers/mailbox/pcc.c
> > @@ -461,8 +461,11 @@ static int __init acpi_pcc_probe(void)
> > count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
> > sizeof(struct acpi_table_pcct), proc,
> > ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
> > - if (count == 0 || count > MAX_PCC_SUBSPACES) {
> > - pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
> > + if (count <= 0 || count > MAX_PCC_SUBSPACES) {
> > + if (count < 0)
> > + pr_warn("Error parsing PCC subspaces from PCCT\n");
> > + else
> > + pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
> > return -EINVAL;
> > }
> >
> >
>
> Thanks, David. Nice catch.
>
> Reviewed-by: Al Stone <[email protected]>

Patch applied, thanks!