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From: Kees Cook <keescook@chromium.org>
To: linux-hardening@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
	Alasdair Kergon <agk@redhat.com>,
	Mike Snitzer <snitzer@redhat.com>,
	dm-devel@redhat.com, linux-kernel@vger.kernel.org
Subject: [PATCH 11/17] dm integrity: Use struct_group() to zero struct journal_sector
Date: Mon, 13 Dec 2021 14:33:25 -0800	[thread overview]
Message-ID: <20211213223331.135412-12-keescook@chromium.org> (raw)
In-Reply-To: <20211213223331.135412-1-keescook@chromium.org>

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.

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 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 6319deccbe09..163c94ca4e5c 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++) {
-- 
2.30.2


  parent reply	other threads:[~2021-12-13 22:34 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-13 22:33 [PATCH 00/17] Enable strict compile-time memcpy() fortify checks Kees Cook
2021-12-13 22:33 ` [PATCH 01/17] KVM: x86: Replace memset() "optimization" with normal per-field writes Kees Cook
2021-12-13 22:33 ` [PATCH 02/17] net/mlx5e: Avoid field-overflowing memcpy() Kees Cook
2021-12-13 22:33 ` [PATCH 03/17] net/mlx5e: Use struct_group() for memcpy() region Kees Cook
2021-12-13 22:33 ` [PATCH 04/17] media: omap3isp: " Kees Cook
2021-12-13 22:33 ` [PATCH 05/17] sata_fsl: " Kees Cook
2021-12-13 22:33 ` [PATCH 06/17] fortify: Detect struct member overflows in memcpy() at compile-time Kees Cook
2021-12-16 11:08   ` Mark Rutland
2021-12-16 11:21     ` Mark Rutland
2021-12-16 18:00     ` Kees Cook
2021-12-17 13:34       ` Mark Rutland
2021-12-13 22:33 ` [PATCH 07/17] fortify: Detect struct member overflows in memmove() " Kees Cook
2021-12-13 22:33 ` [PATCH 08/17] ath11k: Use memset_startat() for clearing queue descriptors Kees Cook
2021-12-14  6:02   ` Kalle Valo
2021-12-14 15:46     ` Kalle Valo
2021-12-14 17:05       ` Kees Cook
2021-12-16 13:50         ` Kalle Valo
2021-12-13 22:33 ` [PATCH 09/17] RDMA/mlx5: Use memset_after() to zero struct mlx5_ib_mr Kees Cook
2021-12-13 22:33 ` [PATCH 10/17] drbd: Use struct_group() to zero algs Kees Cook
2021-12-13 22:33 ` Kees Cook [this message]
2021-12-13 22:33 ` [PATCH 12/17] iw_cxgb4: Use memset_startat() for cpl_t5_pass_accept_rpl Kees Cook
2021-12-13 22:33 ` [PATCH 13/17] intel_th: msu: Use memset_startat() for clearing hw header Kees Cook
2021-12-13 22:33 ` [PATCH 14/17] IB/mthca: Use memset_startat() for clearing mpt_entry Kees Cook
2021-12-13 22:33 ` [PATCH 15/17] scsi: lpfc: Use struct_group() to initialize struct lpfc_cgn_info Kees Cook
2021-12-13 22:33 ` [PATCH 16/17] fortify: Detect struct member overflows in memset() at compile-time Kees Cook
2021-12-13 22:33 ` [PATCH 17/17] fortify: Work around Clang inlining bugs Kees Cook
2021-12-15  0:26 ` [PATCH 00/17] Enable strict compile-time memcpy() fortify checks Jason Gunthorpe
2021-12-17  4:04 ` Martin K. Petersen

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