Unverified Commit f1d325b8 authored by Konstantin Komarov's avatar Konstantin Komarov
Browse files

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: default avatarKonstantin Komarov <almaz.alexandrovich@paragon-software.com>
parent 6a4cd3ea

fs/ntfs3/super.c

+39 −19
Original line number Diff line number Diff line
@@ -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;
@@ -938,22 +945,10 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size, 
	if (bh->b_blocknr && !sb_rdonly(sb)) {

		/*

	     * Alternative boot is ok but primary is not ok.

	 	 * Update primary boot.

	     * Do not update primary boot here 'cause it may be faked boot.

	     * Let ntfs to be mounted and update boot later.

	     */

		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);

		}

		*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 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc) 
		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 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc) 
	put_mount_options(sbi->options);

	put_ntfs(sbi);

	sb->s_fs_info = NULL;

	kfree(boot2);



	return err;

}