linux.git/fs/udf, branch v3.18.72

udf: Fix deadlock between writeback and udf_setsize()

2017-07-27T22:03:28+00:00

commit f2e95355891153f66d4156bf3a142c6489cd78c6 upstream.

udf_setsize() called truncate_setsize() with i_data_sem held. Thus
truncate_pagecache() called from truncate_setsize() could lock a page
under i_data_sem which can deadlock as page lock ranks below
i_data_sem - e. g. writeback can hold page lock and try to acquire
i_data_sem to map a block.

Fix the problem by moving truncate_setsize() calls from under
i_data_sem. It is safe for us to change i_size without holding
i_data_sem as all the places that depend on i_size being stable already
hold inode_lock.

Fixes: 7e49b6f2480cb9a9e7322a91592e56a5c85361f5
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

udf: Check output buffer length when converting name to CS0

2016-02-10T03:56:19+00:00

[ Upstream commit bb00c898ad1ce40c4bb422a8207ae562e9aea7ae ]

If a name contains at least some characters with Unicode values
exceeding single byte, the CS0 output should have 2 bytes per character.
And if other input characters have single byte Unicode values, then
the single input byte is converted to 2 output bytes, and the length
of output becomes larger than the length of input. And if the input
name is long enough, the output length may exceed the allocated buffer
length.

All this means that conversion from UTF8 or NLS to CS0 requires
checking of output length in order to stop when it exceeds the given
output buffer size.

[JK: Make code return -ENAMETOOLONG instead of silently truncating the
name]

CC: stable@vger.kernel.org
Signed-off-by: Andrew Gabbasov 
Signed-off-by: Jan Kara 
Signed-off-by: Sasha Levin

udf: Prevent buffer overrun with multi-byte characters

2016-02-10T03:56:19+00:00

[ Upstream commit ad402b265ecf6fa22d04043b41444cdfcdf4f52d ]

udf_CS0toUTF8 function stops the conversion when the output buffer
length reaches UDF_NAME_LEN-2, which is correct maximum name length,
but, when checking, it leaves the space for a single byte only,
while multi-bytes output characters can take more space, causing
buffer overflow.

Similar error exists in udf_CS0toNLS function, that restricts
the output length to UDF_NAME_LEN, while actual maximum allowed
length is UDF_NAME_LEN-2.

In these cases the output can override not only the current buffer
length field, causing corruption of the name buffer itself, but also
following allocation structures, causing kernel crash.

Adjust the output length checks in both functions to prevent buffer
overruns in case of multi-bytes UTF8 or NLS characters.

CC: stable@vger.kernel.org
Signed-off-by: Andrew Gabbasov 
Signed-off-by: Jan Kara 
Signed-off-by: Sasha Levin

udf: limit the maximum number of indirect extents in a row

2016-02-10T03:55:41+00:00

[ Upstream commit b0918d9f476a8434b055e362b83fa4fd1d462c3f ]

udf_next_aext() just follows extent pointers while extents are marked as
indirect. This can loop forever for corrupted filesystem. Limit number
the of indirect extents we are willing to follow in a row.

[JK: Updated changelog, limit, style]

Signed-off-by: Vegard Nossum 
Cc: stable@vger.kernel.org
Cc: Jan Kara 
Cc: Quentin Casasnovas 
Cc: Andrew Morton 
Signed-off-by: Jan Kara 
Signed-off-by: Sasha Levin

udf: Check length of extended attributes and allocation descriptors

2015-03-06T22:53:02+00:00

commit 23b133bdc452aa441fcb9b82cbf6dd05cfd342d0 upstream.

Check length of extended attributes and allocation descriptors when
loading inodes from disk. Otherwise corrupted filesystems could confuse
the code and make the kernel oops.

Reported-by: Carl Henrik Lunde 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

udf: Remove repeated loads blocksize

2015-03-06T22:53:01+00:00

commit 79144954278d4bb5989f8b903adcac7a20ff2a5a upstream.

Store blocksize in a local variable in udf_fill_inode() since it is used
a lot of times.

Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

udf: Release preallocation on last writeable close

2015-02-06T06:36:03+00:00

commit b07ef35244424cbeda9844198607c7077099c82c upstream.

Commit 6fb1ca92a640 "udf: Fix race between write(2) and close(2)"
changed the condition when preallocation is released. The idea was that
we don't want to release the preallocation for an inode on close when
there are other writeable file descriptors for the inode. However the
condition was written in the opposite way so we released preallocation
only if there were other writeable file descriptors. Fix the problem by
changing the condition properly.

Fixes: 6fb1ca92a6409a9d5b0696447cd4997bc9aaf5a2
Reported-by: Fabian Frederick 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

udf: Check component length before reading it

2015-01-08T18:30:29+00:00

commit e237ec37ec154564f8690c5bd1795339955eeef9 upstream.

Check that length specified in a component of a symlink fits in the
input buffer we are reading. Also properly ignore component length for
component types that do not use it. Otherwise we read memory after end
of buffer for corrupted udf image.

Reported-by: Carl Henrik Lunde 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

udf: Verify symlink size before loading it

2015-01-08T18:30:29+00:00

commit a1d47b262952a45aae62bd49cfaf33dd76c11a2c upstream.

UDF specification allows arbitrarily large symlinks. However we support
only symlinks at most one block large. Check the length of the symlink
so that we don't access memory beyond end of the symlink block.

Reported-by: Carl Henrik Lunde 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

udf: Verify i_size when loading inode

2015-01-08T18:30:28+00:00

commit e159332b9af4b04d882dbcfe1bb0117f0a6d4b58 upstream.

Verify that inode size is sane when loading inode with data stored in
ICB. Otherwise we may get confused later when working with the inode and
inode size is too big.

Reported-by: Carl Henrik Lunde 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman