kernel.git/fs/ext4/super.c, branch linux-3.18.y

ext4: force inode writes when nfsd calls commit_metadata()

2019-01-13T09:07:11Z

commit fde872682e175743e0c3ef939c89e3c6008a1529 upstream. Some time back, nfsd switched from calling vfs_fsync() to using a new commit_metadata() hook in export_operations(). If the file system did not provide a commit_metadata() hook, it fell back to using sync_inode_metadata(). Unfortunately doesn't work on all file systems. In particular, it doesn't work on ext4 due to how the inode gets journalled --- the VFS writeback code will not always call ext4_write_inode(). So we need to provide our own ext4_nfs_commit_metdata() method which calls ext4_write_inode() directly. Google-Bug-Id: 121195940 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: fix possible use after free in ext4_quota_enable

2019-01-13T09:07:11Z

commit 61157b24e60fb3cd1f85f2c76a7b1d628f970144 upstream. The function frees qf_inode via iput but then pass qf_inode to lockdep_set_quota_inode on the failure path. This may result in a use-after-free bug. The patch frees df_inode only when it is never used. Fixes: daf647d2dd5 ("ext4: add lockdep annotations for i_data_sem") Cc: stable@kernel.org # 4.6 Reviewed-by: Jan Kara Signed-off-by: Pan Bian Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix possible leak of sbi->s_group_desc_leak in error path

2018-11-22T06:32:48Z

commit 9e463084cdb22e0b56b2dfbc50461020409a5fd3 upstream. Fixes: bfe0a5f47ada ("ext4: add more mount time checks of the superblock") Reported-by: Vasily Averin Signed-off-by: Theodore Ts'o Cc: stable@kernel.org # 4.18 Signed-off-by: Greg Kroah-Hartman

ext4: add more inode number paranoia checks

2018-10-13T07:09:32Z

commit c37e9e013469521d9adb932d17a1795c139b36db upstream. If there is a directory entry pointing to a system inode (such as a journal inode), complain and declare the file system to be corrupted. Also, if the superblock's first inode number field is too small, refuse to mount the file system. This addresses CVE-2018-10882. https://bugzilla.kernel.org/show_bug.cgi?id=200069 Signed-off-by: Theodore Ts'o [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman

ext4: fix false negatives and false positives in ext4_check_descriptors()

2018-10-13T07:09:31Z

commit 44de022c4382541cebdd6de4465d1f4f465ff1dd upstream. Ext4_check_descriptors() was getting called before s_gdb_count was initialized. So for file systems w/o the meta_bg feature, allocation bitmaps could overlap the block group descriptors and ext4 wouldn't notice. For file systems with the meta_bg feature enabled, there was a fencepost error which would cause the ext4_check_descriptors() to incorrectly believe that the block allocation bitmap overlaps with the block group descriptor blocks, and it would reject the mount. Fix both of these problems. Signed-off-by: Theodore Ts'o [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman

ext4: fix check to prevent initializing reserved inodes

2018-10-13T07:09:31Z

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 [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman

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

2018-10-13T07:09:31Z

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 [bwh: Backported to 3.16: - ext4_read_block_bitmap_nowait() and ext4_read_inode_bitmap() return a pointer (NULL on error) instead of an error code - Open-code sb_rdonly() - Adjust context] Signed-off-by: Ben Hutchings [ghackmann@google.com: forward-port to 3.18: adjust context] Signed-off-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman

ext4: recalucate superblock checksum after updating free blocks/inodes

2018-10-13T07:09:23Z

commit 4274f516d4bc50648a4d97e4f67ecbd7b65cde4a upstream. When mounting the superblock, ext4_fill_super() calculates the free blocks and free inodes and stores them in the superblock. It's not strictly necessary, since we don't use them any more, but it's nice to keep them roughly aligned to reality. Since it's not critical for file system correctness, the code doesn't call ext4_commit_super(). The problem is that it's in ext4_commit_super() that we recalculate the superblock checksum. So if we're not going to call ext4_commit_super(), we need to call ext4_superblock_csum_set() to make sure the superblock checksum is consistent. Most of the time, this doesn't matter, since we end up calling ext4_commit_super() very soon thereafter, and definitely by the time the file system is unmounted. However, it doesn't work in this sequence: mke2fs -Fq -t ext4 /dev/vdc 128M mount /dev/vdc /vdc cp xfstests/git-versions /vdc godown /vdc umount /vdc mount /dev/vdc tune2fs -l /dev/vdc With this commit, the "tune2fs -l" no longer fails. Reported-by: Chengguang Xu Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: add more mount time checks of the superblock

2018-07-11T13:42:25Z

commit bfe0a5f47ada40d7984de67e59a7d3390b9b9ecc upstream. The kernel's ext4 mount-time checks were more permissive than e2fsprogs's libext2fs checks when opening a file system. The superblock is considered too insane for debugfs or e2fsck to operate on it, the kernel has no business trying to mount it. This will make file system fuzzing tools work harder, but the failure cases that they find will be more useful and be easier to evaluate. Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: make sure bitmaps and the inode table don't overlap with bg descriptors

2018-07-11T13:42:25Z

commit 77260807d1170a8cf35dbb06e07461a655f67eee upstream. It's really bad when the allocation bitmaps and the inode table overlap with the block group descriptors, since it causes random corruption of the bg descriptors. So we really want to head those off at the pass. https://bugzilla.kernel.org/show_bug.cgi?id=199865 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

kernel.git/fs/ext4/super.c, branch linux-3.18.y

ext4: force inode writes when nfsd calls commit_metadata()

ext4: fix possible use after free in ext4_quota_enable

ext4: fix possible leak of sbi->s_group_desc_leak in error path

ext4: add more inode number paranoia checks

ext4: fix false negatives *and* false positives in ext4_check_descriptors()

ext4: fix check to prevent initializing reserved inodes

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

ext4: recalucate superblock checksum after updating free blocks/inodes

ext4: add more mount time checks of the superblock

ext4: make sure bitmaps and the inode table don't overlap with bg descriptors

ext4: fix false negatives and false positives in ext4_check_descriptors()