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fs/ntfs3: Do not update primary boot in ntfs_init_from_boot()

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'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>
This commit is contained in:
Konstantin Komarov 2023-05-08 12:09:10 +04:00
parent 6a4cd3ea7d
commit f1d325b8c7
No known key found for this signature in database
GPG Key ID: A9B0331F832407B6
1 changed files with 39 additions and 19 deletions
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58
fs/ntfs3/super.c
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@ -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;
}