As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the purpose specific kcalloc*() function instead of the argument
size * count in the kzalloc*() function.
[1] https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Link: https://github.com/KSPP/linux/issues/162
Signed-off-by: Erick Archer <[email protected]>
---
arch/x86/events/amd/uncore.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 5bf03c575812..9073eb0613cf 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -479,8 +479,8 @@ static int amd_uncore_ctx_init(struct amd_uncore *uncore, unsigned int cpu)
goto fail;
curr->cpu = cpu;
- curr->events = kzalloc_node(sizeof(*curr->events) *
- pmu->num_counters,
+ curr->events = kcalloc_node(pmu->num_counters,
+ sizeof(*curr->events),
GFP_KERNEL, node);
if (!curr->events) {
kfree(curr);
@@ -928,7 +928,7 @@ int amd_uncore_umc_ctx_init(struct amd_uncore *uncore, unsigned int cpu)
uncore->num_pmus += group_num_pmus[gid];
}
- uncore->pmus = kzalloc(sizeof(*uncore->pmus) * uncore->num_pmus,
+ uncore->pmus = kcalloc(uncore->num_pmus, sizeof(*uncore->pmus),
GFP_KERNEL);
if (!uncore->pmus) {
uncore->num_pmus = 0;
--
2.25.1
On 1/16/24 06:58, Erick Archer wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
>
> So, use the purpose specific kcalloc*() function instead of the argument
> size * count in the kzalloc*() function.
>
> [1] https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
>
> Link: https://github.com/KSPP/linux/issues/162
> Signed-off-by: Erick Archer <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Thanks!
--
Gustavo
> ---
> arch/x86/events/amd/uncore.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
> index 5bf03c575812..9073eb0613cf 100644
> --- a/arch/x86/events/amd/uncore.c
> +++ b/arch/x86/events/amd/uncore.c
> @@ -479,8 +479,8 @@ static int amd_uncore_ctx_init(struct amd_uncore *uncore, unsigned int cpu)
> goto fail;
>
> curr->cpu = cpu;
> - curr->events = kzalloc_node(sizeof(*curr->events) *
> - pmu->num_counters,
> + curr->events = kcalloc_node(pmu->num_counters,
> + sizeof(*curr->events),
> GFP_KERNEL, node);
> if (!curr->events) {
> kfree(curr);
> @@ -928,7 +928,7 @@ int amd_uncore_umc_ctx_init(struct amd_uncore *uncore, unsigned int cpu)
> uncore->num_pmus += group_num_pmus[gid];
> }
>
> - uncore->pmus = kzalloc(sizeof(*uncore->pmus) * uncore->num_pmus,
> + uncore->pmus = kcalloc(uncore->num_pmus, sizeof(*uncore->pmus),
> GFP_KERNEL);
> if (!uncore->pmus) {
> uncore->num_pmus = 0;
> --
> 2.25.1
>
>