Commit d82893c5 authored by Pasha Tatashin's avatar Pasha Tatashin Committed by Andrew Morton
Browse files

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: default avatarPasha Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/20240311164638.2015063-6-pasha.tatashin@soleen.com


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Acked-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 90eb270d

kernel/fork.c

+5 −5
Original line number Diff line number Diff line
@@ -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;