• T
    ext4: validate s_reserved_gdt_blocks on mount · 5b9554dc
    Theodore Ts'o 提交于
    If s_reserved_gdt_blocks is extremely large, it's possible for
    ext4_init_block_bitmap(), which is called when ext4 sets up an
    uninitialized block bitmap, to corrupt random kernel memory.  Add the
    same checks which e2fsck has --- it must never be larger than
    blocksize / sizeof(__u32) --- and then add a backup check in
    ext4_init_block_bitmap() in case the superblock gets modified after
    the file system is mounted.
    Reported-by: NVegard Nossum <vegard.nossum@oracle.com>
    Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
    Cc: stable@vger.kernel.org
    5b9554dc
super.c 154.2 KB