CVE-2024-42304

Source
https://nvd.nist.gov/vuln/detail/CVE-2024-42304
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-42304.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2024-42304
Downstream
Related
Published
2024-08-17T09:15:10Z
Modified
2025-08-09T20:01:27Z
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

ext4: make sure the first directory block is not a hole

The syzbot constructs a directory that has no dirblock but is non-inline, i.e. the first directory block is a hole. And no errors are reported when creating files in this directory in the following flow.

ext4_mknod
 ...
  ext4_add_entry
    // Read block 0
    ext4_read_dirblock(dir, block, DIRENT)
      bh = ext4_bread(NULL, inode, block, 0)
      if (!bh && (type == INDEX || type == DIRENT_HTREE))
      // The first directory block is a hole
      // But type == DIRENT, so no error is reported.

After that, we get a directory block without '.' and '..' but with a valid dentry. This may cause some code that relies on dot or dotdot (such as makeindexeddir()) to crash.

Therefore when ext4readdirblock() finds that the first directory block is a hole report that the filesystem is corrupted and return an error to avoid loading corrupted data from disk causing something bad.

References

Affected packages