Junglewise Threat Intelligence

CVE-2024-47699: Linux Kernel NULL pointer dereference in nilfs2 btree_insert

CVE-2024-47699 · Severity: medium · CVSS 5.5 · Published 2024-10-21

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's NILFS2 file system could allow a local user to crash the system. The issue occurs when the system attempts to process a specially crafted or corrupted file system image. This could lead to a denial-of-service condition, impacting system availability and ongoing operations.

Technical details

A NULL pointer dereference exists in nilfs_btree_prepare_insert() within the NILFS2 file system implementation. The vulnerability is triggered when a B-tree root node is inconsistent (e.g., having a height greater than 2 but zero child nodes). In such cases, nilfs_btree_do_lookup() fails to initialize the block buffer head (path[x].bp_bh), which is subsequently accessed by nilfs_btree_get_nonroot_node(). An attacker with the ability to mount a corrupted NILFS2 image or manipulate filesystem structures can trigger this flaw to cause a kernel panic (Denial of Service). The fix introduces additional sanity checks in nilfs_btree_root_broken() to validate the relationship between node level and child count.

Affected products

  • Linux Linux Kernel 2.6.30 to 5.10.226, 5.11 to 5.15.167, 5.16 to 6.1.112, 6.2 to 6.6.53, 6.7 to 6.10.12, 6.11 to 6.11.1

Timeline

  • 2024-09-04: patched: Initial patch authored
  • 2024-10-21: advisory: CVE published by NVD

References

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