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| author | Kees Cook <keescook@chromium.org> | 2021-05-20 15:30:56 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-10-18 12:28:52 -0700 |
| commit | a2c5062f391b970b9ecbe0f579c5e22822577ea3 (patch) | |
| tree | ec532542380b1d027d619a2c0aaf0d2c45489e30 | |
| parent | 6dbefad40815a61aecbcf9b552e87ef57ab8cc7d (diff) | |
| download | linux-a2c5062f391b970b9ecbe0f579c5e22822577ea3.tar.gz | |
btrfs: Use memset_startat() to clear end of struct
In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Use memset_startat() so memset() doesn't get confused about writing beyond the destination member that is intended to be the starting point of zeroing through the end of the struct. Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: David Sterba <dsterba@suse.com> Cc: linux-btrfs@vger.kernel.org Reviewed-by: Nikolay Borisov <nborisov@suse.com> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | fs/btrfs/root-tree.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 702dc5441f03..12ceb14a1141 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -39,10 +39,8 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot, need_reset = 1; } if (need_reset) { - memset(&item->generation_v2, 0, - sizeof(*item) - offsetof(struct btrfs_root_item, - generation_v2)); - + /* Clear all members from generation_v2 onwards. */ + memset_startat(item, 0, generation_v2); generate_random_guid(item->uuid); } } |