CVE-2023-52989

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

firewire: fix memory leak for payload of request subaction to IEC 61883-1 FCP region

This patch is fix for Linux kernel v2.6.33 or later.

For request subaction to IEC 61883-1 FCP region, Linux FireWire subsystem have had an issue of use-after-free. The subsystem allows multiple user space listeners to the region, while data of the payload was likely released before the listeners execute read(2) to access to it for copying to user space.

The issue was fixed by a commit 281e20323ab7 (firewire: core: fix use-after-free regression in FCP handler). The object of payload is duplicated in kernel space for each listener. When the listener executes ioctl(2) with FW_CDEV_IOC_SEND_RESPONSE request, the object is going to be released.

However, it causes memory leak since the commit relies on call of release_request() in drivers/firewire/core-cdev.c. Against the expectation, the function is never called due to the design of release_client_resource(). The function delegates release task to caller when called with non-NULL fourth argument. The implementation of ioctl_send_response() is the case. It should release the object explicitly.

This commit fixes the bug.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/356ff89acdbe6a66019154bc7eb2d300f5b15103
• https://git.kernel.org/stable/c/531390a243ef47448f8bad01c186c2787666bf4d
• https://git.kernel.org/stable/c/53785fd9b315583cf029e39f72b73d23704a2253
• https://git.kernel.org/stable/c/5f4543c9382ae2d5062f6aa4fecae0c9258d0b0e
• https://git.kernel.org/stable/c/b2cd3947d116bb9ba7ff097b5fc747a8956764db
• https://git.kernel.org/stable/c/c8bdc88216f09cb7387fedbdf613524367328616
• https://git.kernel.org/stable/c/d5a2dcee53fa6e6e2822f93cb3f1b0cd23163bee