kernel/git/stable/linux.git/fs/udf/super.c, branch linux-4.9.y

udf: Check LVID earlier

2021-09-22T09:42:58+00:00

[ Upstream commit 781d2a9a2fc7d0be53a072794dc03ef6de770f3d ] We were checking validity of LVID entries only when getting implementation use information from LVID in udf_sb_lvidiu(). However if the LVID is suitably corrupted, it can cause problems also to code such as udf_count_free() which doesn't use udf_sb_lvidiu(). So check validity of LVID already when loading it from the disk and just disable LVID altogether when it is not valid. Reported-by: syzbot+7fbfe5fed73ebb675748@syzkaller.appspotmail.com Signed-off-by: Jan Kara Signed-off-by: Sasha Levin

udf: Limit sparing table size

2020-10-29T08:05:44+00:00

[ Upstream commit 44ac6b829c4e173fdf6df18e6dd86aecf9a3dc99 ] Although UDF standard allows it, we don't support sparing table larger than a single block. Check it during mount so that we don't try to access memory beyond end of buffer. Reported-by: syzbot+9991561e714f597095da@syzkaller.appspotmail.com Signed-off-by: Jan Kara Signed-off-by: Sasha Levin

udf: Fix free space reporting for metadata and virtual partitions

2020-02-28T14:42:30+00:00

[ Upstream commit a4a8b99ec819ca60b49dc582a4287ef03411f117 ] Free space on filesystems with metadata or virtual partition maps currently gets misreported. This is because these partitions are just remapped onto underlying real partitions from which keep track of free blocks. Take this remapping into account when counting free blocks as well. Reviewed-by: Pali Rohár Reported-by: Pali Rohár Signed-off-by: Jan Kara Signed-off-by: Sasha Levin

udf: Allow mounting volumes with incorrect identification strings

2018-12-08T12:05:08+00:00

commit b54e41f5efcb4316b2f30b30c2535cc194270373 upstream. Commit c26f6c615788 ("udf: Fix conversion of 'dstring' fields to UTF8") started to be more strict when checking whether converted strings are properly formatted. Sudip reports that there are DVDs where the volume identification string is actually too long - UDF reports: [ 632.309320] UDF-fs: incorrect dstring lengths (32/32) during mount and fails the mount. This is mostly harmless failure as we don't need volume identification (and even less volume set identification) for anything. So just truncate the volume identification string if it is too long and replace it with 'Invalid' if we just cannot convert it for other reasons. This keeps slightly incorrect media still mountable. CC: stable@vger.kernel.org Fixes: c26f6c615788 ("udf: Fix conversion of 'dstring' fields to UTF8") Reported-and-tested-by: Sudip Mukherjee Signed-off-by: Jan Kara Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

udf: Provide saner default for invalid uid / gid

2018-05-30T05:50:49+00:00

[ Upstream commit 116e5258e4115aca0c64ac0bf40ded3b353ed626 ] Currently when UDF filesystem is recorded without uid / gid (ids are set to -1), we will assign INVALID_[UG]ID to vfs inode unless user uses uid= and gid= mount options. In such case filesystem could not be modified in any way as VFS refuses to modify files with invalid ids (even by root). This is confusing to users and not very useful default since such media mode is generally used for removable media. Use overflow[ug]id instead so that at least root can modify the filesystem. Reported-by: Steve Kenton Reviewed-by: Pali Rohár Signed-off-by: Jan Kara Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

udf: Avoid overflow when session starts at large offset

2017-12-20T09:07:33+00:00

[ Upstream commit abdc0eb06964fe1d2fea6dd1391b734d0590365d ] When session starts beyond offset 2^31 the arithmetics in udf_check_vsd() would overflow. Make sure the computation is done in large enough type. Reported-by: Cezary Sliwa Signed-off-by: Jan Kara Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

udf: Use correct partition reference number for metadata

2016-05-19T11:00:35+00:00

UDF/OSTA terminology is confusing. Partition Numbers (PNs) are arbitrary 16-bit values, one for each physical partition in the volume. Partition Reference Numbers (PRNs) are indices into the the Partition Map Table and do not necessarily equal the PN of the mapped partition. The current metadata code mistakenly uses the PN instead of the PRN when mapping metadata blocks to physical/sparable blocks. Windows-created UDF 2.5 discs for some reason use large, arbitrary PNs, resulting in mount failure and KASAN read warnings in udf_read_inode(). For example, a NetBSD UDF 2.5 partition might look like this: PRN PN Type --- -- ---- 0 0 Sparable 1 0 Metadata Since PRN == PN, we are fine. But Windows could gives us: PRN PN Type --- ---- ---- 0 8192 Sparable 1 8192 Metadata So udf_read_inode() will start out by checking the partition length in sbi->s_partmaps[8192], which is obviously out of bounds. Fix this by creating a new field (s_phys_partition_ref) in struct udf_meta_data, referencing whatever physical or sparable map has the same partition number as the metadata partition. [JK: Add comment about s_phys_partition_ref, change its name] Signed-off-by: Alden Tondettar Signed-off-by: Jan Kara

udf: Prevent stack overflow on corrupted filesystem mount

2016-04-26T06:25:07+00:00

Presently, a corrupted or malicious UDF filesystem containing a very large number (or cycle) of Logical Volume Integrity Descriptor extent indirections may trigger a stack overflow and kernel panic in udf_load_logicalvolint() on mount. Replace the unnecessary recursion in udf_load_logicalvolint() with simple iteration. Set an arbitrary limit of 1000 indirections (which would have almost certainly overflowed the stack without this fix), and treat such cases as if there were no LVID. Signed-off-by: Alden Tondettar Signed-off-by: Jan Kara

udf: Fix conversion of 'dstring' fields to UTF8

2016-04-25T13:18:50+00:00

Commit 9293fcfbc1812a22ad5ce1b542eb90c1bbe01be1 ("udf: Remove struct ustr as non-needed intermediate storage"), while getting rid of 'struct ustr', does not take any special care of 'dstring' fields and effectively use fixed field length instead of actual string length, encoded in the last byte of the field. Also, commit 484a10f49387e4386bf2708532e75bf78ffea2cb ("udf: Merge linux specific translation into CS0 conversion function") introduced checking of the length of the string being converted, requiring proper alignment to number of bytes constituing each character. The UDF volume identifier is represented as a 32-bytes 'dstring', and needs to be converted from CS0 to UTF8, while mounting UDF filesystem. The changes in mentioned commits can in some cases lead to incorrect handling of volume identifier: - if the actual string in 'dstring' is of maximal length and does not have zero bytes separating it from dstring encoded length in last byte, that last byte may be included in conversion, thus making incorrect resulting string; - if the identifier is encoded with 2-bytes characters (compression code is 16), the length of 31 bytes (32 bytes of field length minus 1 byte of compression code), taken as the string length, is reported as an incorrect (unaligned) length, and the conversion fails, which in its turn leads to volume mounting failure. This patch introduces handling of 'dstring' encoded length field in udf_CS0toUTF8 function, that is used in all and only cases when 'dstring' fields are converted. Currently these cases are processing of Volume Identifier and Volume Set Identifier fields. The function is also renamed to udf_dstrCS0toUTF8 to distinctly indicate that it handles 'dstring' input. Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara

udf: Remove struct ustr as non-needed intermediate storage

2016-02-09T12:05:23+00:00

Although 'struct ustr' tries to structurize the data by combining the string and its length, it doesn't actually make much benefit, since it saves only one parameter, but introduces an extra copying of the whole buffer, serving as an intermediate storage. It looks quite inefficient and not actually needed. This commit gets rid of the struct ustr by changing the parameters of some functions appropriately. Also, it removes using 'dstring' type, since it doesn't make much sense too. Just using the occasion, add a 'const' qualifier to udf_get_filename to make consistent parameters sets. Signed-off-by: Andrew Gabbasov Signed-off-by: Jan Kara