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 Reviewed-by: Gustavo A. R. Silva <gustavo...@kernel.org> Signed-off-by: Erick Archer <erick.arc...@outlook.com> --- Changes in v2: - Add the "Reviewed-by:" tag. - Rebase against linux-next. Previous versions: v1 -> https://lore.kernel.org/linux-hardening/20240116125813.3754-1-erick.arc...@gmx.com/ Hi everyone, This patch seems to be lost. Gustavo reviewed it on January 16, 2024 but the patch has not been applied since. Thanks, Erick --- 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 4ccb8fa483e6..61c0a2114183 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
