CVE-2024-42104

Summary

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

nilfs2: add missing check for inode numbers on directory entries

Syzbot reported that mounting and unmounting a specific pattern of corrupted nilfs2 filesystem images causes a use-after-free of metadata file inodes, which triggers a kernel bug in lru_add_fn().

As Jan Kara pointed out, this is because the link count of a metadata file gets corrupted to 0, and nilfs_evict_inode(), which is called from iput(), tries to delete that inode (ifile inode in this case).

The inconsistency occurs because directories containing the inode numbers of these metadata files that should not be visible in the namespace are read without checking.

Fix this issue by treating the inode numbers of these internal files as errors in the sanity check helper when reading directory folios/pages.

Also thanks to Hillf Danton and Matthew Wilcox for their initial mm-layer analysis.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < c33c2b0d92aa1c2262d999b2598ad6fbd53bd479affected
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < 07c176e7acc5579c133bb923ab21316d192d0a95affected
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < 2f2fa9cf7c3537958a82fbe8c8595a5eb0861ad7affected
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < b11e8fb93ea5eefb2e4e719497ea177a58ff6131affected
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < 1b7d549ed2c1fa202c751b69423a0d3a6bd5a180affected
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < 3ab40870edb883b9633dc5cd55f5a2a11afa618daffected
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < 265fff1a01cdc083aeaf0d934c929db5cc64aebfaffected
LinuxLinux2ba466d74ed74f073257f86e61519cb8f8f46184 < bb76c6c274683c8570ad788f79d4b875bde0e458affected
LinuxLinux2.6.30affected
LinuxLinux0 < 2.6.30unaffected
LinuxLinux4.19.318 <= 4.19.*unaffected
LinuxLinux5.4.280 <= 5.4.*unaffected
LinuxLinux5.10.222 <= 5.10.*unaffected
LinuxLinux5.15.163 <= 5.15.*unaffected
LinuxLinux6.1.98 <= 6.1.*unaffected
LinuxLinux6.6.39 <= 6.6.*unaffected
LinuxLinux6.9.9 <= 6.9.*unaffected
LinuxLinux6.10 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References