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

ext4: fix spectre gadget in ext4_mb_regular_allocator()

2018-08-24T11:07:15+00:00

commit 1a5d5e5d51e75a5bca67dadbcea8c841934b7b85 upstream. 'ac->ac_g_ex.fe_len' is a user-controlled value which is used in the derivation of 'ac->ac_2order'. 'ac->ac_2order', in turn, is used to index arrays which makes it a potential spectre gadget. Fix this by sanitizing the value assigned to 'ac->ac2_order'. This covers the following accesses found with the help of smatch: * fs/ext4/mballoc.c:1896 ext4_mb_simple_scan_group() warn: potential spectre issue 'grp->bb_counters' [w] (local cap) * fs/ext4/mballoc.c:445 mb_find_buddy() warn: potential spectre issue 'EXT4_SB(e4b->bd_sb)->s_mb_offsets' [r] (local cap) * fs/ext4/mballoc.c:446 mb_find_buddy() warn: potential spectre issue 'EXT4_SB(e4b->bd_sb)->s_mb_maxs' [r] (local cap) Suggested-by: Josh Poimboeuf Signed-off-by: Jeremy Cline Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

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: fix inline data updates with checksums enabled

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

commit 362eca70b53389bddf3143fe20f53dcce2cfdf61 upstream. The inline data code was updating the raw inode directly; this is problematic since if metadata checksums are enabled, ext4_mark_inode_dirty() must be called to update the inode's checksum. In addition, the jbd2 layer requires that get_write_access() be called before the metadata buffer is modified. Fix both of these problems. https://bugzilla.kernel.org/show_bug.cgi?id=200443 Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

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

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

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 Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

dax: change bdev_dax_supported() to support boolean returns

2018-07-11T14:31:33+00:00

commit 80660f20252d6f76c9f203874ad7c7a4a8508cf8 upstream. The function return values are confusing with the way the function is named. We expect a true or false return value but it actually returns 0/-errno. This makes the code very confusing. Changing the return values to return a bool where if DAX is supported then return true and no DAX support returns false. Signed-off-by: Dave Jiang Signed-off-by: Ross Zwisler Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman

fs: allow per-device dax status checking for filesystems

2018-07-11T14:31:33+00:00

commit ba23cba9b3bdc967aabdc6ff1e3e9b11ce05bb4f upstream. Change bdev_dax_supported so it takes a bdev parameter. This enables multi-device filesystems like xfs to check that a dax device can work for the particular filesystem. Once that's in place, actually fix all the parts of XFS where we need to be able to distinguish between datadev and rtdev. This patch fixes the problem where we screw up the dax support checking in xfs if the datadev and rtdev have different dax capabilities. Signed-off-by: Darrick J. Wong [rez: Re-added __bdev_dax_supported() for !CONFIG_FS_DAX cases] Signed-off-by: Ross Zwisler Reviewed-by: Eric Sandeen Signed-off-by: Greg Kroah-Hartman

ext4: check superblock mapped prior to committing

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

commit a17712c8e4be4fa5404d20e9cd3b2b21eae7bc56 upstream. This patch attempts to close a hole leading to a BUG seen with hot removals during writes [1]. A block device (NVME namespace in this test case) is formatted to EXT4 without partitions. It's mounted and write I/O is run to a file, then the device is hot removed from the slot. The superblock attempts to be written to the drive which is no longer present. The typical chain of events leading to the BUG: ext4_commit_super() __sync_dirty_buffer() submit_bh() submit_bh_wbc() BUG_ON(!buffer_mapped(bh)); This fix checks for the superblock's buffer head being mapped prior to syncing. [1] https://www.spinics.net/lists/linux-ext4/msg56527.html Signed-off-by: Jon Derrick Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: add more mount time checks of the superblock

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

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: add more inode number paranoia checks

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

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 Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

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

ext4: fix spectre gadget in ext4_mb_regular_allocator()

ext4: fix check to prevent initializing reserved inodes

ext4: check for allocation block validity with block group locked

ext4: fix inline data updates with checksums enabled

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

dax: change bdev_dax_supported() to support boolean returns

fs: allow per-device dax status checking for filesystems

ext4: check superblock mapped prior to committing

ext4: add more mount time checks of the superblock

ext4: add more inode number paranoia checks

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