kernel/git/stable/linux.git/fs/ext4/ialloc.c, branch linux-4.17.y

ext4: fix check to prevent initializing reserved inodes

2018-08-03T05:48:03+00:00

commit 5012284700775a4e6e3fbe7eac4c543c4874b559 upstream. Commit 8844618d8aa7: "ext4: only look at the bg_flags field if it is valid" will complain if block group zero does not have the EXT4_BG_INODE_ZEROED flag set. Unfortunately, this is not correct, since a freshly created file system has this flag cleared. It gets almost immediately after the file system is mounted read-write --- but the following somewhat unlikely sequence will end up triggering a false positive report of a corrupted file system: mkfs.ext4 /dev/vdc mount -o ro /dev/vdc /vdc mount -o remount,rw /dev/vdc Instead, when initializing the inode table for block group zero, test to make sure that itable_unused count is not too large, since that is the case that will result in some or all of the reserved inodes getting cleared. This fixes the failures reported by Eric Whiteney when running generic/230 and generic/231 in the the nojournal test case. Fixes: 8844618d8aa7 ("ext4: only look at the bg_flags field if it is valid") Reported-by: Eric Whitney Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: check for allocation block validity with block group locked

2018-08-03T05:48:03+00:00

commit 8d5a803c6a6ce4ec258e31f76059ea5153ba46ef upstream. With commit 044e6e3d74a3: "ext4: don't update checksum of new initialized bitmaps" the buffer valid bit will get set without actually setting up the checksum for the allocation bitmap, since the checksum will get calculated once we actually allocate an inode or block. If we are doing this, then we need to (re-)check the verified bit after we take the block group lock. Otherwise, we could race with another process reading and verifying the bitmap, which would then complain about the checksum being invalid. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1780137 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: only look at the bg_flags field if it is valid

2018-07-11T14:31:29+00:00

commit 8844618d8aa7a9973e7b527d038a2a589665002c upstream. The bg_flags field in the block group descripts is only valid if the uninit_bg or metadata_csum feature is enabled. We were not consistently looking at this field; fix this. Also block group #0 must never have uninitialized allocation bitmaps, or need to be zeroed, since that's where the root inode, and other special inodes are set up. Check for these conditions and mark the file system as corrupted if they are detected. This addresses CVE-2018-10876. https://bugzilla.kernel.org/show_bug.cgi?id=199403 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: add validity checks for bitmap block numbers

2018-03-27T03:54:10+00:00

An privileged attacker can cause a crash by mounting a crafted ext4 image which triggers a out-of-bounds read in the function ext4_valid_block_bitmap() in fs/ext4/balloc.c. This issue has been assigned CVE-2018-1093. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199181 BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1560782 Reported-by: Wen Xu Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

ext4: don't update checksum of new initialized bitmaps

2018-02-19T19:16:47+00:00

When reading the inode or block allocation bitmap, if the bitmap needs to be initialized, do not update the checksum in the block group descriptor. That's because we're not set up to journal those changes. Instead, just set the verified bit on the bitmap block, so that it's not necessary to validate the checksum. When a block or inode allocation actually happens, at that point the checksum will be calculated, and update of the bg descriptor block will be properly journalled. Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

ext4: use 'sbi' instead of 'EXT4_SB(sb)'

2018-01-11T18:17:49+00:00

We could use 'sbi' instead of 'EXT4_SB(sb)' to make code more elegant. Signed-off-by: Jun Piao Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara

ext4: add missing error check in __ext4_new_inode()

2017-12-11T04:44:11+00:00

It's possible for ext4_get_acl() to return an ERR_PTR. So we need to add a check for this case in __ext4_new_inode(). Otherwise on an error we can end up oops the kernel. This was getting triggered by xfstests generic/388, which is a test which exercises the shutdown code path. Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2017-11-14T20:59:42+00:00

Pull ext4 updates from Ted Ts'o: - Add support for online resizing of file systems with bigalloc - Fix a two data corruption bugs involving DAX, as well as a corruption bug after a crash during a racing fallocate and delayed allocation. - Finally, a number of cleanups and optimizations. * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: improve smp scalability for inode generation ext4: add support for online resizing with bigalloc ext4: mention noload when recovering on read-only device Documentation: fix little inconsistencies ext4: convert timers to use timer_setup() jbd2: convert timers to use timer_setup() ext4: remove duplicate extended attributes defs ext4: add ext4_should_use_dax() ext4: add sanity check for encryption + DAX ext4: prevent data corruption with journaling + DAX ext4: prevent data corruption with inline data + DAX ext4: fix interaction between i_size, fallocate, and delalloc after a crash ext4: retry allocations conservatively ext4: Switch to iomap for SEEK_HOLE / SEEK_DATA ext4: Add iomap support for inline data iomap: Add IOMAP_F_DATA_INLINE flag iomap: Switch from blkno to disk offset

ext4: improve smp scalability for inode generation

2017-11-09T03:23:20+00:00

->s_next_generation is protected by s_next_gen_lock but its usage pattern is very primitive. We don't actually need sequentially increasing new generation numbers, so let's use prandom_u32() instead. Reported-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o

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