In the Linux kernel, the following vulnerability has been resolved:
ext4: fix buffer_head leak in ext4_init_orphan_info
ext4_init_orphan_info() reads orphan file blocks with ext4_bread()
and stores the returned buffer_head in oi->of_binfo[i].ob_bh.
If ext4_bread() succeeds but the orphan block magic or checksum
validation fails, the function jumps to out_free. However, the old
out_free loop starts releasing buffers from i – 1, so the current
buffer_head at index i is skipped.
This leaks the buffer_head reference obtained by ext4_bread() on the
bad magic and bad checksum error paths.
Fix this by tracking the number of successfully read buffer_heads and
releasing exactly those buffer_heads on the error path.
