From c66fd01277939634c624c8340838682d9d4fd839 Mon Sep 17 00:00:00 2001
From: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Date: Thu, 14 Sep 2023 13:22:53 +0100
Subject: [PATCH 04/11] libfsimage/xfs: Add compile-time check to libfsimage
Adds the common tools include folder to the -I compile flags
of libfsimage. This allows us to use:
xen-tools/common-macros.h:BUILD_BUG_ON()
With it, statically assert a sanitized "blocklog - SECTOR_BITS" cannot
underflow.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
tools/libfsimage/common.mk | 2 +-
tools/libfsimage/xfs/fsys_xfs.c | 4 +++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/tools/libfsimage/common.mk b/tools/libfsimage/common.mk
index 4fc8c6679599..e4336837d045 100644
--- a/tools/libfsimage/common.mk
+++ b/tools/libfsimage/common.mk
@@ -1,7 +1,7 @@
include $(XEN_ROOT)/tools/Rules.mk
FSDIR := $(libdir)/xenfsimage
-CFLAGS += -Wno-unknown-pragmas -I$(XEN_ROOT)/tools/libfsimage/common/ -DFSIMAGE_FSDIR=\"$(FSDIR)\"
+CFLAGS += -Wno-unknown-pragmas -I$(XEN_ROOT)/tools/libfsimage/common/ $(CFLAGS_xeninclude) -DFSIMAGE_FSDIR=\"$(FSDIR)\"
CFLAGS += -D_GNU_SOURCE
LDFLAGS += -L../common/
diff --git a/tools/libfsimage/xfs/fsys_xfs.c b/tools/libfsimage/xfs/fsys_xfs.c
index e4eb7e1ee26f..4a8dd6f2397b 100644
--- a/tools/libfsimage/xfs/fsys_xfs.c
+++ b/tools/libfsimage/xfs/fsys_xfs.c
@@ -19,6 +19,7 @@
#include <stdbool.h>
#include <xenfsimage_grub.h>
+#include <xen-tools/libs.h>
#include "xfs.h"
#define MAX_LINK_COUNT 8
@@ -477,9 +478,10 @@ xfs_mount (fsi_file_t *ffi, const char *options)
xfs.agblklog = super.sb_agblklog;
/* Derived from sanitized parameters */
+ BUILD_BUG_ON(XFS_SB_BLOCKLOG_MIN < SECTOR_BITS);
+ xfs.bdlog = super.sb_blocklog - SECTOR_BITS;
xfs.bsize = 1 << super.sb_blocklog;
xfs.blklog = super.sb_blocklog;
- xfs.bdlog = super.sb_blocklog - SECTOR_BITS;
xfs.isize = 1 << super.sb_inodelog;
xfs.dirbsize = 1 << (super.sb_blocklog + super.sb_dirblklog);
xfs.inopblog = super.sb_blocklog - super.sb_inodelog;
--
2.42.0