* [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf
@ 2017-12-13 22:45 Gustavo A. R. Silva
2017-12-15 18:18 ` George Cherian
2017-12-16 1:47 ` Rafael J. Wysocki
0 siblings, 2 replies; 3+ messages in thread
From: Gustavo A. R. Silva @ 2017-12-13 22:45 UTC (permalink / raw)
To: Rafael J. Wysocki, Len Brown, George Cherian
Cc: linux-acpi, linux-kernel, Gustavo A. R. Silva
If pcc_ss_id is less than 0, there is a negative array index read
before verifying pcc_ss_id is not a negative value.
Fix this by removing the code that triggers this issue.
Notice that this code is already properly placed after the check
on pcc_ss_id at line 1182: pcc_ss_data = pcc_data[pcc_ss_id];
Addresses-Coverity-ID: 1426090 ("Negative array index read")
Fixes: 1ecbd7170d65 ("ACPI / CPPC: Fix KASAN global out of bounds warning")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
drivers/acpi/cppc_acpi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 30e84cc..06ea474 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1171,7 +1171,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
struct cpc_register_resource *desired_reg;
int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
- struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
+ struct cppc_pcc_data *pcc_ss_data;
int ret = 0;
if (!cpc_desc || pcc_ss_id < 0) {
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf
2017-12-13 22:45 [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf Gustavo A. R. Silva
@ 2017-12-15 18:18 ` George Cherian
2017-12-16 1:47 ` Rafael J. Wysocki
1 sibling, 0 replies; 3+ messages in thread
From: George Cherian @ 2017-12-15 18:18 UTC (permalink / raw)
To: Gustavo A. R. Silva, Rafael J. Wysocki, Len Brown, George Cherian
Cc: linux-acpi, linux-kernel
On Thursday 14 December 2017 04:15 AM, Gustavo A. R. Silva wrote:
> If pcc_ss_id is less than 0, there is a negative array index read
> before verifying pcc_ss_id is not a negative value.
>
> Fix this by removing the code that triggers this issue.
>
> Notice that this code is already properly placed after the check
> on pcc_ss_id at line 1182: pcc_ss_data = pcc_data[pcc_ss_id];
>
> Addresses-Coverity-ID: 1426090 ("Negative array index read")
> Fixes: 1ecbd7170d65 ("ACPI / CPPC: Fix KASAN global out of bounds warning")
Reviewed-by: George Cherian <george.cherian@cavium.com>
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
> drivers/acpi/cppc_acpi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 30e84cc..06ea474 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -1171,7 +1171,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
> struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
> struct cpc_register_resource *desired_reg;
> int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
> - struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
> + struct cppc_pcc_data *pcc_ss_data;
> int ret = 0;
>
> if (!cpc_desc || pcc_ss_id < 0) {
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf
2017-12-13 22:45 [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf Gustavo A. R. Silva
2017-12-15 18:18 ` George Cherian
@ 2017-12-16 1:47 ` Rafael J. Wysocki
1 sibling, 0 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2017-12-16 1:47 UTC (permalink / raw)
To: Gustavo A. R. Silva; +Cc: Len Brown, George Cherian, linux-acpi, linux-kernel
On Wednesday, December 13, 2017 11:45:41 PM CET Gustavo A. R. Silva wrote:
> If pcc_ss_id is less than 0, there is a negative array index read
> before verifying pcc_ss_id is not a negative value.
>
> Fix this by removing the code that triggers this issue.
>
> Notice that this code is already properly placed after the check
> on pcc_ss_id at line 1182: pcc_ss_data = pcc_data[pcc_ss_id];
>
> Addresses-Coverity-ID: 1426090 ("Negative array index read")
> Fixes: 1ecbd7170d65 ("ACPI / CPPC: Fix KASAN global out of bounds warning")
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
> drivers/acpi/cppc_acpi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 30e84cc..06ea474 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -1171,7 +1171,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
> struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
> struct cpc_register_resource *desired_reg;
> int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
> - struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
> + struct cppc_pcc_data *pcc_ss_data;
> int ret = 0;
>
> if (!cpc_desc || pcc_ss_id < 0) {
>
I applied a patch from Coling Ian King that did the same thing and was
posted eaelier.
Thanks,
Rafael
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-12-13 22:45 [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf Gustavo A. R. Silva
2017-12-15 18:18 ` George Cherian
2017-12-16 1:47 ` Rafael J. Wysocki
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