From f069c7ab6cfb07edf9e3dc2071928225587794f1 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Mon, 13 Dec 2021 14:33:25 -0800
Subject: [PATCH] dm integrity: Use struct_group() to zero struct
journal_sector
Git-commit: f069c7ab6cfb07edf9e3dc2071928225587794f1
Patch-mainline: v5.17-rc1
References: jsc#PED-2765
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.
Add struct_group() to mark region of struct journal_sector that should be
initialized to zero.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm-integrity.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 7af242de3202..eb4b5e52bd6f 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -121,8 +121,10 @@ struct journal_entry {
#define JOURNAL_MAC_SIZE (JOURNAL_MAC_PER_SECTOR * JOURNAL_BLOCK_SECTORS)
struct journal_sector {
- __u8 entries[JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR];
- __u8 mac[JOURNAL_MAC_PER_SECTOR];
+ struct_group(sectors,
+ __u8 entries[JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR];
+ __u8 mac[JOURNAL_MAC_PER_SECTOR];
+ );
commit_id_t commit_id;
};
@@ -2870,7 +2872,8 @@ static void init_journal(struct dm_integrity_c *ic, unsigned start_section,
wraparound_section(ic, &i);
for (j = 0; j < ic->journal_section_sectors; j++) {
struct journal_sector *js = access_journal(ic, i, j);
- memset(&js->entries, 0, JOURNAL_SECTOR_DATA);
+ BUILD_BUG_ON(sizeof(js->sectors) != JOURNAL_SECTOR_DATA);
+ memset(&js->sectors, 0, sizeof(js->sectors));
js->commit_id = dm_integrity_commit_id(ic, i, j, commit_seq);
}
for (j = 0; j < ic->journal_section_entries; j++) {
--
2.35.3