From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: Alasdair Kergon <agk@redhat.com>,
dm-devel@redhat.com, linux-hardening@vger.kernel.org,
Mike Snitzer <snitzer@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [dm-devel] [PATCH] dm integrity: Use struct_group() to zero struct journal_sector
Date: Mon, 13 Dec 2021 17:25:38 -0600 [thread overview]
Message-ID: <20211213232538.GB60133@embeddedor> (raw)
In-Reply-To: <20211118203640.1288585-1-keescook@chromium.org>
On Thu, Nov 18, 2021 at 12:36:40PM -0800, Kees Cook wrote:
> 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>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks
--
Gustavo
> ---
> 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
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://listman.redhat.com/mailman/listinfo/dm-devel
>
>
>
>
prev parent reply other threads:[~2021-12-13 23:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-18 20:36 [PATCH] dm integrity: Use struct_group() to zero struct journal_sector Kees Cook
2021-12-13 23:25 ` Gustavo A. R. Silva [this message]
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