linux-kernel - [PATCH v1 08/32] kho: don't unpreserve memory during abort

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]

Message-ID: <20250625231838.1897085-9-pasha.tatashin@soleen.com>
Date: Wed, 25 Jun 2025 23:17:55 +0000
From: Pasha Tatashin <pasha.tatashin@...een.com>
To: pratyush@...nel.org,
	jasonmiu@...gle.com,
	graf@...zon.com,
	changyuanl@...gle.com,
	pasha.tatashin@...een.com,
	rppt@...nel.org,
	dmatlack@...gle.com,
	rientjes@...gle.com,
	corbet@....net,
	rdunlap@...radead.org,
	ilpo.jarvinen@...ux.intel.com,
	kanie@...ux.alibaba.com,
	ojeda@...nel.org,
	aliceryhl@...gle.com,
	masahiroy@...nel.org,
	akpm@...ux-foundation.org,
	tj@...nel.org,
	yoann.congal@...le.fr,
	mmaurer@...gle.com,
	roman.gushchin@...ux.dev,
	chenridong@...wei.com,
	axboe@...nel.dk,
	mark.rutland@....com,
	jannh@...gle.com,
	vincent.guittot@...aro.org,
	hannes@...xchg.org,
	dan.j.williams@...el.com,
	david@...hat.com,
	joel.granados@...nel.org,
	rostedt@...dmis.org,
	anna.schumaker@...cle.com,
	song@...nel.org,
	zhangguopeng@...inos.cn,
	linux@...ssschuh.net,
	linux-kernel@...r.kernel.org,
	linux-doc@...r.kernel.org,
	linux-mm@...ck.org,
	gregkh@...uxfoundation.org,
	tglx@...utronix.de,
	mingo@...hat.com,
	bp@...en8.de,
	dave.hansen@...ux.intel.com,
	x86@...nel.org,
	hpa@...or.com,
	rafael@...nel.org,
	dakr@...nel.org,
	bartosz.golaszewski@...aro.org,
	cw00.choi@...sung.com,
	myungjoo.ham@...sung.com,
	yesanishhere@...il.com,
	Jonathan.Cameron@...wei.com,
	quic_zijuhu@...cinc.com,
	aleksander.lobakin@...el.com,
	ira.weiny@...el.com,
	andriy.shevchenko@...ux.intel.com,
	leon@...nel.org,
	lukas@...ner.de,
	bhelgaas@...gle.com,
	wagi@...nel.org,
	djeffery@...hat.com,
	stuart.w.hayes@...il.com,
	ptyadav@...zon.de,
	lennart@...ttering.net,
	brauner@...nel.org,
	linux-api@...r.kernel.org,
	linux-fsdevel@...r.kernel.org
Subject: [PATCH v1 08/32] kho: don't unpreserve memory during abort

KHO allows clients to preserve memory regions at any point before the
KHO state is finalized. The finalization process itself involves KHO
performing its own actions, such as serializing the overall
preserved memory map.

If this finalization process is aborted, the current implementation
destroys KHO's internal memory tracking structures
(`kho_out.ser.track.orders`). This behavior effectively unpreserves
all memory from KHO's perspective, regardless of whether those
preservations were made by clients before the finalization attempt
or by KHO itself during finalization.

This premature unpreservation is incorrect. An abort of the
finalization process should only undo actions taken by KHO as part of
that specific finalization attempt. Individual memory regions
preserved by clients prior to finalization should remain preserved,
as their lifecycle is managed by the clients themselves. These
clients might still need to call kho_unpreserve_folio() or
kho_unpreserve_phys() based on their own logic, even after a KHO
finalization attempt is aborted.

Signed-off-by: Pasha Tatashin <pasha.tatashin@...een.com>
---
 kernel/kexec_handover.c | 21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

diff --git a/kernel/kexec_handover.c b/kernel/kexec_handover.c
index d9e947eac041..7ec9b0826a6e 100644
--- a/kernel/kexec_handover.c
+++ b/kernel/kexec_handover.c
@@ -778,31 +778,12 @@ EXPORT_SYMBOL_GPL(kho_unpreserve_phys);
 
 static int __kho_abort(void)
 {
-	int err = 0;
-	unsigned long order;
-	struct kho_mem_phys *physxa;
-
-	xa_for_each(&kho_out.track.orders, order, physxa) {
-		struct kho_mem_phys_bits *bits;
-		unsigned long phys;
-
-		xa_for_each(&physxa->phys_bits, phys, bits)
-			kfree(bits);
-
-		xa_destroy(&physxa->phys_bits);
-		kfree(physxa);
-	}
-	xa_destroy(&kho_out.track.orders);
-
 	if (kho_out.preserved_mem_map) {
 		kho_mem_ser_free(kho_out.preserved_mem_map);
 		kho_out.preserved_mem_map = NULL;
 	}
 
-	if (err)
-		pr_err("Failed to abort KHO finalization: %d\n", err);
-
-	return err;
+	return 0;
 }
 
 int kho_abort(void)
-- 
2.50.0.727.gbf7dc18ff4-goog