CVE-2026-63811
Description
A flaw was found in the Linux kernel's f2fs filesystem. During an atomic write operation, the system may attempt to decrypt data using an incorrect encryption context, specifically when the original file is unencrypted but its Copy-On-Write (COW) inode is encrypted. This mismatch can lead to a null-pointer dereference, causing a kernel crash and resulting in a Denial of Service (DoS) for the affected system. A local user could potentially trigger this vulnerability.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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