bobfuzzer/CVE

In the Linux kernel 5.0.0-rc7 (as distributed in ubuntu/linux.git on kernel.ubuntu.com), mounting a crafted f2fs filesystem image and performing some operations can lead to slab-out-of-bounds read access in ttm_put_pages in drivers/gpu/drm/ttm/ttm_page_alloc.c. This is related to the vmwgfx or ttm module.

In the Linux kernel 5.0.21, mounting a crafted f2fs filesystem image can cause a NULL pointer dereference in f2fs_recover_fsync_data in fs/f2fs/recovery.c. This is related to F2FS_P_SB in fs/f2fs/f2fs.h.

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image and performing some operations can cause slab-out-of-bounds write access in __btrfs_map_block in fs/btrfs/volumes.c, because a value of 1 for the number of data stripes is mishandled.

In the Linux kernel 5.0.21, mounting a crafted f2fs filesystem image can cause __remove_dirty_segment slab-out-of-bounds write access because an array is bounded by the number of dirty types (8) but the array index can exceed this.

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in __mutex_lock in kernel/locking/mutex.c. This is related to mutex_can_spin_on_owner in kernel/locking/mutex.c, __btrfs_qgroup_free_meta in fs/btrfs/qgroup.c, and btrfs_insert_delayed_items in fs/btrfs/delayed-inode.c.

In the Linux kernel 5.0.21 and 5.3.11, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in try_merge_free_space in fs/btrfs/free-space-cache.c because the pointer to a left data structure can be the same as the pointer to a right data structure.

In the Linux kernel 5.0.21, mounting a crafted f2fs filesystem image can lead to slab-out-of-bounds read access in f2fs_build_segment_manager in fs/f2fs/segment.c, related to init_min_max_mtime in fs/f2fs/segment.c (because the second argument to get_seg_entry is not validated).

In the Linux kernel 5.0.21, mounting a crafted ext4 filesystem image, performing some operations, and unmounting can lead to a use-after-free in ext4_put_super in fs/ext4/super.c, related to dump_orphan_list in fs/ext4/super.c.

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image can lead to slab-out-of-bounds write access in index_rbio_pages in fs/btrfs/raid56.c.

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing some operations, and unmounting can lead to a use-after-free in btrfs_queue_work in fs/btrfs/async-thread.c.

In the Linux kernel 5.3.11, mounting a crafted btrfs image twice can cause an rwsem_down_write_slowpath use-after-free because (in rwsem_can_spin_on_owner in kernel/locking/rwsem.c) rwsem_owner_flags returns an already freed pointer,

In the Linux kernel before 5.2, a setxattr operation, after a mount of a crafted ext4 image, can cause a slab-out-of-bounds write access because of an ext4_xattr_set_entry use-after-free in fs/ext4/xattr.c when a large old_size value is used in a memset call, aka CID-345c0dbf3a30.

ext4_empty_dir in fs/ext4/namei.c in the Linux kernel through 5.3.12 allows a NULL pointer dereference because ext4_read_dirblock(inode,0,DIRENT_HTREE) can be zero.

btrfs_root_node in fs/btrfs/ctree.c in the Linux kernel through 5.3.12 allows a NULL pointer dereference because rcu_dereference(root->node) can be zero.

__btrfs_free_extent in fs/btrfs/extent-tree.c in the Linux kernel through 5.3.12 calls btrfs_print_leaf in a certain ENOENT case, which allows local users to obtain potentially sensitive information about register values via the dmesg program. NOTE: The BTRFS development team disputes this issues as not being a vulnerability because “1) The kernel provide facilities to restrict access to dmesg - dmesg_restrict=1 sysctl option. So it's really up to the system administrator to judge whether dmesg access shall be disallowed or not. 2) WARN/WARN_ON are widely used macros in the linux kernel. If this CVE is considered valid this would mean there are literally thousands CVE lurking in the kernel - something which clearly is not the case.