Executive brief
A vulnerability was identified in the Linux kernel's ext4 file system component. A logic error in how the system handles file data structures (extents) can lead to a memory leak. Over time, this could degrade system performance or lead to a denial-of-service condition if the kernel exhausts available memory.
Technical details
A memory leak exists in fs/ext4/extents.c within the ext4_ext_shift_extents() function. When the function encounters a NULL extent during its processing loop, it returns an -EFSCORRUPTED error immediately. However, it fails to release the 'path' structure previously allocated via ext4_find_extent(). This flaw allows an attacker or a corrupted filesystem to trigger repeated memory allocations that are never freed. The fix involves modifying the error path to use a 'goto out' statement, ensuring that the cleanup logic which releases the path is executed before the function returns.
Affected products
- Linux Linux Kernel All versions including and prior to 6.13-rc4
Timeline
- 2025-12-25: other: Patch submitted by developer
- 2026-02-26: patched: Patch committed to stable tree
- 2026-05-27: advisory: CVE published
References
- https://git.kernel.org/stable/c/12615ab4bfb69678e5d961b28bb70040299e51b1
- https://git.kernel.org/stable/c/1bce219ee5512cf179ba40cf114945a14a16e21f
- https://git.kernel.org/stable/c/2f4b1052246ca646bb17bfe0f53df2fdf9729b58
- https://git.kernel.org/stable/c/4a79fde8db7eba7f1128d971ceba4e3c9ac84aec
- https://git.kernel.org/stable/c/7e807cb8603b7664fa630a696cd891d9a03c248d
- https://git.kernel.org/stable/c/afc5e61e1a07b2b833bd72cbee36ecce9cd901e2
- https://git.kernel.org/stable/c/bd7b52557e4a3ccd7595fdb3a585f1257de57935