kernel/linux.git/fs/isofs/dir.c, branch v6.12.80

isofs: fix KMSAN uninit-value bug in do_isofs_readdir()

2025-04-10T12:39:22+00:00

[ Upstream commit 81a82e8f33880793029cd6f8a766fb13b737e6a7 ] In do_isofs_readdir() when assigning the variable "struct iso_directory_record *de" the b_data field of the buffer_head is accessed and an offset is added to it, the size of b_data is 2048 and the offset size is 2047, meaning "de = (struct iso_directory_record *) (bh->b_data + offset);" yields the final byte of the 2048 sized b_data block. The first byte of the directory record (de_len) is then read and found to be 31, meaning the directory record size is 31 bytes long. The directory record is defined by the structure: struct iso_directory_record { __u8 length; // 1 byte __u8 ext_attr_length; // 1 byte __u8 extent[8]; // 8 bytes __u8 size[8]; // 8 bytes __u8 date[7]; // 7 bytes __u8 flags; // 1 byte __u8 file_unit_size; // 1 byte __u8 interleave; // 1 byte __u8 volume_sequence_number[4]; // 4 bytes __u8 name_len; // 1 byte char name[]; // variable size } __attribute__((packed)); The fixed portion of this structure occupies 33 bytes. Therefore, a valid directory record must be at least 33 bytes long (even without considering the variable-length name field). Since de_len is only 31, it is insufficient to contain the complete fixed header. The code later hits the following sanity check that compares de_len against the sum of de->name_len and sizeof(struct iso_directory_record): if (de_len < de->name_len[0] + sizeof(struct iso_directory_record)) { ... } Since the fixed portion of the structure is 33 bytes (up to and including name_len member), a valid record should have de_len of at least 33 bytes; here, however, de_len is too short, and the field de->name_len (located at offset 32) is accessed even though it lies beyond the available 31 bytes. This access on the corrupted isofs data triggers a KASAN uninitialized memory warning. The fix would be to first verify that de_len is at least sizeof(struct iso_directory_record) before accessing any fields like de->name_len. Reported-by: syzbot Tested-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=812641c6c3d7586a1613 Fixes: 2deb1acc653c ("isofs: fix access to unallocated memory when reading corrupted filesystem") Signed-off-by: Qasim Ijaz Signed-off-by: Jan Kara Link: https://patch.msgid.link/20250211195900.42406-1-qasdev00@gmail.com Signed-off-by: Sasha Levin

isofs: remove redundant continue statement

2021-06-17T15:11:42+00:00

The continue statement in the while-loop has no effect, remove it. Addresses-Coverity: ("Continue has no effect") Link: https://lore.kernel.org/r/20210617120837.11994-1-colin.king@canonical.com Signed-off-by: Colin Ian King Signed-off-by: Jan Kara

isofs: release buffer head before return

2021-01-25T16:57:38+00:00

Release the buffer_head before returning error code in do_isofs_readdir() and isofs_find_entry(). Fixes: 2deb1acc653c ("isofs: fix access to unallocated memory when reading corrupted filesystem") Link: https://lore.kernel.org/r/20210118120455.118955-1-bianpan2016@163.com Signed-off-by: Pan Bian Signed-off-by: Jan Kara

Update email address

2018-09-30T02:47:48+00:00

Redirect some older email addresses that are in the git logs. Signed-off-by: Matthew Wilcox

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

isofs: switch to ->iterate_shared()

2016-05-09T16:53:03+00:00

Signed-off-by: Al Viro

get_acorn_filename(): deobfuscate a bit

2016-05-09T15:42:20+00:00

Lots of Idiotic Silly Parentheses is -> that way... What that condition checks is that there's exactly 32 bytes between the end of name and the end of entire drectory record. Signed-off-by: Al Viro

[readdir] convert isofs

2013-06-29T08:56:47+00:00

Signed-off-by: Al Viro

new helper: file_inode(file)

2013-02-23T04:31:31+00:00

Signed-off-by: Al Viro

isofs: Remove global fs lock

2011-07-22T23:42:12+00:00

sbi->s_mutex isn't needed for isofs at all so we can just remove it. Generally, since isofs is always mounted read-only, filesystem structure cannot change under us. So buffer_head contents stays constant after it's filled in. That leaves us with possible changes of global data structures. Superblock changes only during filesystem mount (even remount does not change it), inodes are only filled in during reading from disk. So there are no changes of these structures to bother about. Arguments why sbi->s_mutex can be removed at each place: isofs_readdir: Accesses sb, inode, filp, local variables => s_mutex not needed isofs_lookup: Protected by directory's i_mutex. Accesses sb, inode, dentry, local variables => s_mutex not needed rock_ridge_symlink_readpage: Protected by page lock. Accesses sb, inode, local variables => s_mutex not needed. Signed-off-by: Jan Kara Signed-off-by: Al Viro