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| author | Steven J. Magnani <steve.magnani@digidescorp.com> | 2019-08-14 15:50:02 +0300 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2019-08-26 12:17:55 +0300 |
| commit | ab9a3a737284b3d9e1d2ba43a0ef31b3ef2e2417 (patch) | |
| tree | da1ecd5168487841b078727bfcb357edc1172e15 /fs/udf | |
| parent | 56db1991690f076c2a7e3b2a226629cd10901690 (diff) | |
| download | linux-ab9a3a737284b3d9e1d2ba43a0ef31b3ef2e2417.tar.xz | |
udf: reduce leakage of blocks related to named streams
Windows is capable of creating UDF files having named streams.
One example is the "Zone.Identifier" stream attached automatically
to files downloaded from a network. See:
https://msdn.microsoft.com/en-us/library/dn392609.aspx
Modification of a file having one or more named streams in Linux causes
the stream directory to become detached from the file, essentially leaking
all blocks pertaining to the file's streams.
Fix by saving off information about an inode's streams when reading it,
for later use when its on-disk data is updated.
Link: https://lore.kernel.org/r/20190814125002.10869-1-steve@digidescorp.com
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/udf')
| -rw-r--r-- | fs/udf/inode.c | 24 | ||||
| -rw-r--r-- | fs/udf/super.c | 2 | ||||
| -rw-r--r-- | fs/udf/udf_i.h | 5 |
3 files changed, 29 insertions, 2 deletions
diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 9bb18311a22f..54eee39f2698 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1485,6 +1485,8 @@ reread: iinfo->i_lenEAttr = le32_to_cpu(fe->lengthExtendedAttr); iinfo->i_lenAlloc = le32_to_cpu(fe->lengthAllocDescs); iinfo->i_checkpoint = le32_to_cpu(fe->checkpoint); + iinfo->i_streamdir = 0; + iinfo->i_lenStreams = 0; } else { inode->i_blocks = le64_to_cpu(efe->logicalBlocksRecorded) << (inode->i_sb->s_blocksize_bits - 9); @@ -1498,6 +1500,16 @@ reread: iinfo->i_lenEAttr = le32_to_cpu(efe->lengthExtendedAttr); iinfo->i_lenAlloc = le32_to_cpu(efe->lengthAllocDescs); iinfo->i_checkpoint = le32_to_cpu(efe->checkpoint); + + /* Named streams */ + iinfo->i_streamdir = (efe->streamDirectoryICB.extLength != 0); + iinfo->i_locStreamdir = + lelb_to_cpu(efe->streamDirectoryICB.extLocation); + iinfo->i_lenStreams = le64_to_cpu(efe->objectSize); + if (iinfo->i_lenStreams >= inode->i_size) + iinfo->i_lenStreams -= inode->i_size; + else + iinfo->i_lenStreams = 0; } inode->i_generation = iinfo->i_unique; @@ -1760,9 +1772,19 @@ static int udf_update_inode(struct inode *inode, int do_sync) iinfo->i_ext.i_data, inode->i_sb->s_blocksize - sizeof(struct extendedFileEntry)); - efe->objectSize = cpu_to_le64(inode->i_size); + efe->objectSize = + cpu_to_le64(inode->i_size + iinfo->i_lenStreams); efe->logicalBlocksRecorded = cpu_to_le64(lb_recorded); + if (iinfo->i_streamdir) { + struct long_ad *icb_lad = &efe->streamDirectoryICB; + + icb_lad->extLocation = + cpu_to_lelb(iinfo->i_locStreamdir); + icb_lad->extLength = + cpu_to_le32(inode->i_sb->s_blocksize); + } + udf_adjust_time(iinfo, inode->i_atime); udf_adjust_time(iinfo, inode->i_mtime); udf_adjust_time(iinfo, inode->i_ctime); diff --git a/fs/udf/super.c b/fs/udf/super.c index f34e06b4d8fa..00e2d7190b52 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -151,9 +151,11 @@ static struct inode *udf_alloc_inode(struct super_block *sb) ei->i_unique = 0; ei->i_lenExtents = 0; + ei->i_lenStreams = 0; ei->i_next_alloc_block = 0; ei->i_next_alloc_goal = 0; ei->i_strat4096 = 0; + ei->i_streamdir = 0; init_rwsem(&ei->i_data_sem); ei->cached_extent.lstart = -1; spin_lock_init(&ei->i_extent_cache_lock); diff --git a/fs/udf/udf_i.h b/fs/udf/udf_i.h index 2ef0e212f08a..00d773d1b7cf 100644 --- a/fs/udf/udf_i.h +++ b/fs/udf/udf_i.h @@ -42,12 +42,15 @@ struct udf_inode_info { unsigned i_efe : 1; /* extendedFileEntry */ unsigned i_use : 1; /* unallocSpaceEntry */ unsigned i_strat4096 : 1; - unsigned reserved : 26; + unsigned i_streamdir : 1; + unsigned reserved : 25; union { struct short_ad *i_sad; struct long_ad *i_lad; __u8 *i_data; } i_ext; + struct kernel_lb_addr i_locStreamdir; + __u64 i_lenStreams; struct rw_semaphore i_data_sem; struct udf_ext_cache cached_extent; /* Spinlock for protecting extent cache */ |