libext2fs: Add sanity checks to ext2fs_{block,inode}_alloc_stats

If ext2fs_inode_alloc_stats2() or ext2fs_block_alloc_stats() is passed
an insanely large inode or block number, it's possible for these
functions to overrun an array boundary and cause the calling program
to crash with a memory error.

Detect this case, and since these functions don't return an error
code, print a warning message, much like we do in ext2fs_warn_bitmap2().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/alloc_stats.c b/lib/ext2fs/alloc_stats.c
index 97661dc..d523b43 100644 (file)
--- a/lib/ext2fs/alloc_stats.c
+++ b/lib/ext2fs/alloc_stats.c
@@ -20,6 +20,13 @@ void ext2fs_inode_alloc_stats2(ext2_filsys fs, ext2_ino_t ino,
 {
        int     group = ext2fs_group_of_ino(fs, ino);
 
+#ifndef OMIT_COM_ERR
+       if (ino > fs->super->s_inodes_count) {
+               com_err("ext2fs_inode_alloc_stats2", 0,
+                       "Illegal inode number: %lu", ino);
+               return;
+       }
+#endif
        if (inuse > 0)
                ext2fs_mark_inode_bitmap(fs->inode_map, ino);
        else
@@ -58,6 +65,13 @@ void ext2fs_block_alloc_stats(ext2_filsys fs, blk_t blk, int inuse)
 {
        int     group = ext2fs_group_of_blk(fs, blk);
 
+#ifndef OMIT_COM_ERR
+       if (blk >= fs->super->s_blocks_count) {
+               com_err("ext2fs_block_alloc_stats2", 0,
+                       "Illegal block number: %lu", blk);
+               return;
+       }
+#endif
        if (inuse > 0)
                ext2fs_mark_block_bitmap(fs->block_map, blk);
        else