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authorKonstantin Komarov <almaz.alexandrovich@paragon-software.com>2023-05-08 11:09:10 +0300
committerKonstantin Komarov <almaz.alexandrovich@paragon-software.com>2023-07-02 23:21:26 +0300
commitf1d325b8c75e90487b1691fee0199669ea94fff1 (patch)
tree9cdbf0c54b587dee13d59f64513086106d7eb18e /fs/ntfs3
parent6a4cd3ea7d771be17177d95ff67d22cfa2a38b50 (diff)
downloadlinux-f1d325b8c75e90487b1691fee0199669ea94fff1.tar.xz
fs/ntfs3: Do not update primary boot in ntfs_init_from_boot()
'cause it may be faked boot. Let ntfs to be mounted and update boot later. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Diffstat (limited to 'fs/ntfs3')
-rw-r--r--fs/ntfs3/super.c58
1 files changed, 39 insertions, 19 deletions
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index ecf899d571d8..2b48b45238ea 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -711,9 +711,16 @@ static u32 true_sectors_per_clst(const struct NTFS_BOOT *boot)
/*
* ntfs_init_from_boot - Init internal info from on-disk boot sector.
+ *
+ * NTFS mount begins from boot - special formatted 512 bytes.
+ * There are two boots: the first and the last 512 bytes of volume.
+ * The content of boot is not changed during ntfs life.
+ *
+ * NOTE: ntfs.sys checks only first (primary) boot.
+ * chkdsk checks both boots.
*/
static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
- u64 dev_size)
+ u64 dev_size, struct NTFS_BOOT **boot2)
{
struct ntfs_sb_info *sbi = sb->s_fs_info;
int err;
@@ -937,23 +944,11 @@ check_boot:
if (bh->b_blocknr && !sb_rdonly(sb)) {
/*
- * Alternative boot is ok but primary is not ok.
- * Update primary boot.
- */
- struct buffer_head *bh0 = sb_getblk(sb, 0);
- if (bh0) {
- if (buffer_locked(bh0))
- __wait_on_buffer(bh0);
-
- lock_buffer(bh0);
- memcpy(bh0->b_data, boot, sizeof(*boot));
- set_buffer_uptodate(bh0);
- mark_buffer_dirty(bh0);
- unlock_buffer(bh0);
- if (!sync_dirty_buffer(bh0))
- ntfs_warn(sb, "primary boot is updated");
- put_bh(bh0);
- }
+ * Alternative boot is ok but primary is not ok.
+ * Do not update primary boot here 'cause it may be faked boot.
+ * Let ntfs to be mounted and update boot later.
+ */
+ *boot2 = kmemdup(boot, sizeof(*boot), GFP_NOFS | __GFP_NOWARN);
}
out:
@@ -1000,6 +995,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
u16 *shared;
struct MFT_REF ref;
bool ro = sb_rdonly(sb);
+ struct NTFS_BOOT *boot2 = NULL;
ref.high = 0;
@@ -1030,7 +1026,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
/* Parse boot. */
err = ntfs_init_from_boot(sb, bdev_logical_block_size(bdev),
- bdev_nr_bytes(bdev));
+ bdev_nr_bytes(bdev), &boot2);
if (err)
goto out;
@@ -1412,6 +1408,29 @@ load_root:
goto put_inode_out;
}
+ if (boot2) {
+ /*
+ * Alternative boot is ok but primary is not ok.
+ * Volume is recognized as NTFS. Update primary boot.
+ */
+ struct buffer_head *bh0 = sb_getblk(sb, 0);
+ if (bh0) {
+ if (buffer_locked(bh0))
+ __wait_on_buffer(bh0);
+
+ lock_buffer(bh0);
+ memcpy(bh0->b_data, boot2, sizeof(*boot2));
+ set_buffer_uptodate(bh0);
+ mark_buffer_dirty(bh0);
+ unlock_buffer(bh0);
+ if (!sync_dirty_buffer(bh0))
+ ntfs_warn(sb, "primary boot is updated");
+ put_bh(bh0);
+ }
+
+ kfree(boot2);
+ }
+
return 0;
put_inode_out:
@@ -1424,6 +1443,7 @@ out:
put_mount_options(sbi->options);
put_ntfs(sbi);
sb->s_fs_info = NULL;
+ kfree(boot2);
return err;
}