diff mbox series

[5.16,50/53] xen/pvcalls: use alloc/free_pages_exact()

Message ID	20220310140813.271374697@linuxfoundation.org
State	New
Headers	show Return-Path: <stable-owner@kernel.org> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org, Simon Gaiser <simon@invisiblethingslab.com>, Juergen Gross <jgross@suse.com>, Jan Beulich <jbeulich@suse.com> Subject: [PATCH 5.16 50/53] xen/pvcalls: use alloc/free_pages_exact() Date: Thu, 10 Mar 2022 15:09:55 +0100 Message-Id: <20220310140813.271374697@linuxfoundation.org> In-Reply-To: <20220310140811.832630727@linuxfoundation.org> References: <20220310140811.832630727@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	None \| expand [5.16,02/53] x86/speculation: Add eIBRS + Retpoline options [5.16,04/53] x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting [5.16,07/53] x86/speculation: Warn about Spectre v2 LFENCE mitigation [5.16,08/53] x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT [5.16,10/53] ARM: early traps initialisation [5.16,14/53] arm64: add ID_AA64ISAR2_EL1 sys register [5.16,16/53] arm64: cpufeature: add HWCAP for FEAT_RPRES [5.16,18/53] arm64: spectre: Rename spectre_v4_patch_fw_mitigation_conduit [5.16,19/53] KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A [5.16,21/53] arm64: entry: Free up another register on kptis tramp_exit path [5.16,23/53] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary [5.16,25/53] arm64: entry: Move trampoline macros out of ifdefd section [5.16,27/53] arm64: entry: Allow the trampoline text to occupy multiple pages [5.16,29/53] arm64: entry: Add vectors that have the bhb mitigation sequences [5.16,30/53] arm64: entry: Add macro for reading symbol addresses from the trampoline [5.16,34/53] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated [5.16,35/53] arm64: Use the clearbhb instruction in mitigations [5.16,39/53] ARM: Do not use NOCROSSREFS directive with ld.lld [5.16,41/53] ARM: fix build warning in proc-v7-bugs.c [5.16,43/53] xen/grant-table: add gnttab_try_end_foreign_access() [5.16,44/53] xen/blkfront: dont use gnttab_query_foreign_access() for mapped status [5.16,46/53] xen/scsifront: dont use gnttab_query_foreign_access() for mapped status [5.16,47/53] xen/gntalloc: dont use gnttab_query_foreign_access() [5.16,49/53] xen/9p: use alloc/free_pages_exact() [5.16,50/53] xen/pvcalls: use alloc/free_pages_exact() [5.16,52/53] xen/netfront: react properly to failing gnttab_end_foreign_access_ref()

Commit Message

Greg KH March 10, 2022, 2:09 p.m. UTC

From: Juergen Gross <jgross@suse.com>

Commit b0576cc9c6b843d99c6982888d59a56209341888 upstream.

Instead of __get_free_pages() and free_pages() use alloc_pages_exact()
and free_pages_exact(). This is in preparation of a change of
gnttab_end_foreign_access() which will prohibit use of high-order
pages.

This is part of CVE-2022-23041 / XSA-396.

Reported-by: Simon Gaiser <simon@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/xen/pvcalls-front.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff mbox series

Patch

--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -337,8 +337,8 @@  static void free_active_ring(struct sock
 	if (!map->active.ring)
 		return;
 
-	free_pages((unsigned long)map->active.data.in,
-			map->active.ring->ring_order);
+	free_pages_exact(map->active.data.in,
+			 PAGE_SIZE << map->active.ring->ring_order);
 	free_page((unsigned long)map->active.ring);
 }
 
@@ -352,8 +352,8 @@  static int alloc_active_ring(struct sock
 		goto out;
 
 	map->active.ring->ring_order = PVCALLS_RING_ORDER;
-	bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-					PVCALLS_RING_ORDER);
+	bytes = alloc_pages_exact(PAGE_SIZE << PVCALLS_RING_ORDER,
+				  GFP_KERNEL | __GFP_ZERO);
 	if (!bytes)
 		goto out;