libext2fs: fix arguments passed to ->block_alloc_stats_range

In ext2fs_block_alloc_stats_range, we use @num as the loop counter but
then pass it to the callback and @blk as the loop cursor.  This means
that the range passed to e2fsck_block_alloc_stats_range starts beyond
the range that was actually freed and has a length of zero, which is not
at all correct.

Fix this by saving the original values and passing those instead.

Cc: linux-ext4@vger.kernel.org # v1.43
Fixes: 647e8786156061 ("libext2fs: add new hooks to support large allocations")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/175182663005.1984706.2711154041137486922.stgit@frogsfrogsfrogs
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/alloc_stats.c b/lib/ext2fs/alloc_stats.c
index 6f98bcc7cbd5f3e6587c826f70bf942c995f449a..95a6438f252e0fdf47b3c9f7955a5fd5ede99797 100644 (file)
--- a/lib/ext2fs/alloc_stats.c
+++ b/lib/ext2fs/alloc_stats.c
@@ -110,6 +110,9 @@ void ext2fs_set_block_alloc_stats_callback(ext2_filsys fs,
 void ext2fs_block_alloc_stats_range(ext2_filsys fs, blk64_t blk,
                                    blk_t num, int inuse)
 {
+       const blk64_t orig_blk = blk;
+       const blk_t orig_num = num;
+
 #ifndef OMIT_COM_ERR
        if (blk + num > ext2fs_blocks_count(fs->super)) {
                com_err("ext2fs_block_alloc_stats_range", 0,
@@ -147,7 +150,7 @@ void ext2fs_block_alloc_stats_range(ext2_filsys fs, blk64_t blk,
        ext2fs_mark_super_dirty(fs);
        ext2fs_mark_bb_dirty(fs);
        if (fs->block_alloc_stats_range)
-               (fs->block_alloc_stats_range)(fs, blk, num, inuse);
+               (fs->block_alloc_stats_range)(fs, orig_blk, orig_num, inuse);
 }
 
 void ext2fs_set_block_alloc_stats_range_callback(ext2_filsys fs,