linux-kernel - [RFC 05/14] fork: check charging success before zeroing stack

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon, 11 Mar 2024 16:46:29 +0000
From: Pasha Tatashin <pasha.tatashin@...een.com>
To: linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	akpm@...ux-foundation.org,
	x86@...nel.org,
	bp@...en8.de,
	brauner@...nel.org,
	bristot@...hat.com,
	bsegall@...gle.com,
	dave.hansen@...ux.intel.com,
	dianders@...omium.org,
	dietmar.eggemann@....com,
	eric.devolder@...cle.com,
	hca@...ux.ibm.com,
	hch@...radead.org,
	hpa@...or.com,
	jacob.jun.pan@...ux.intel.com,
	jgg@...pe.ca,
	jpoimboe@...nel.org,
	jroedel@...e.de,
	juri.lelli@...hat.com,
	kent.overstreet@...ux.dev,
	kinseyho@...gle.com,
	kirill.shutemov@...ux.intel.com,
	lstoakes@...il.com,
	luto@...nel.org,
	mgorman@...e.de,
	mic@...ikod.net,
	michael.christie@...cle.com,
	mingo@...hat.com,
	mjguzik@...il.com,
	mst@...hat.com,
	npiggin@...il.com,
	peterz@...radead.org,
	pmladek@...e.com,
	rick.p.edgecombe@...el.com,
	rostedt@...dmis.org,
	surenb@...gle.com,
	tglx@...utronix.de,
	urezki@...il.com,
	vincent.guittot@...aro.org,
	vschneid@...hat.com,
	pasha.tatashin@...een.com
Subject: [RFC 05/14] fork: check charging success before zeroing stack

No need to do zero cahced stack if memcg charge fails, so move the
charging attempt before the memset operation.

Signed-off-by: Pasha Tatashin <pasha.tatashin@...een.com>
---
 kernel/fork.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index a35f4008afa0..6a2f2c85e09f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -271,6 +271,11 @@ 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);
 
@@ -279,11 +284,6 @@ 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;
-- 
2.44.0.278.ge034bb2e1d-goog