From d82893c52a64dd5698362ba1d7cb232a18839c87 Mon Sep 17 00:00:00 2001 From: Pasha Tatashin Date: Fri, 9 May 2025 08:29:28 +0200 Subject: [PATCH] fork: check charging success before zeroing stack No need to do zero cached stack if memcg charge fails, so move the charging attempt before the memset operation. [linus.walleij@linaro.org: rebased] Link: https://lkml.kernel.org/r/20250509-fork-fixes-v3-3-e6c69dd356f2@linaro.org Signed-off-by: Pasha Tatashin Link: https://lore.kernel.org/20240311164638.2015063-6-pasha.tatashin@soleen.com Signed-off-by: Linus Walleij Acked-by: Mike Rapoport (Microsoft) Signed-off-by: Andrew Morton --- kernel/fork.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index 8b8457562740..d6907c49ee87 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -280,6 +280,11 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node) if (!vm_area) continue; + if (memcg_charge_kernel_stack(vm_area)) { + vfree(vm_area->addr); + return -ENOMEM; + } + /* Reset stack metadata. */ kasan_unpoison_range(vm_area->addr, THREAD_SIZE); @@ -288,11 +293,6 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node) /* Clear stale pointers from reused stack. */ memset(stack, 0, THREAD_SIZE); - if (memcg_charge_kernel_stack(vm_area)) { - vfree(vm_area->addr); - return -ENOMEM; - } - tsk->stack_vm_area = vm_area; tsk->stack = stack; return 0; -- 2.51.0