Junglewise Threat Intelligence

CVE-2024-49883: Linux Kernel ext4 use-after-free in ext4_ext_insert_extent

CVE-2024-49883 · Severity: high · CVSS 7.8 · Published 2024-10-21

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability exists in the Linux kernel's ext4 file system, which is widely used for data storage. A flaw in how the system manages memory when writing data can lead to a system crash or potentially allow an attacker to gain unauthorized access to data. This issue primarily affects the stability and security of systems using the ext4 file system.

Technical details

A use-after-free (UAF) vulnerability exists in the ext4 subsystem of the Linux kernel. The flaw occurs in 'ext4_ext_insert_extent()' when 'ext4_ext_create_new_leaf()' triggers a reallocation of the extent path via 'ext4_find_extent()'. If the depth of the extent tree exceeds the current path's maximum depth, the existing path is freed and a new one is allocated; however, the caller may continue to use the stale pointer. A local attacker can exploit this to cause a kernel panic (DoS) or potentially achieve privilege escalation. The fix ensures the path pointer is updated from the pointer-to-pointer argument after the leaf creation call.

Affected products

  • Linux Linux Kernel 3.18 to 4.19.323, 4.20 to 5.4.285, 5.5 to 5.10.227, 5.11 to 5.15.168, 5.16 to 6.1.113, 6.2 to 6.6.55, 6.7 to 6.10.14, 6.11 to 6.11.3

Timeline

  • 2024-08-22: patched: Initial patch authored
  • 2024-10-21: advisory: NVD publication date

References

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