CVE-2024-53198

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

xen: Fix the issue of resource not being properly released in xenbus_dev_probe()

This patch fixes an issue in the function xenbus_dev_probe(). In the xenbus_dev_probe() function, within the if (err) branch at line 313, the program incorrectly returns err directly without releasing the resources allocated by err = drv->probe(dev, id). As the return value is non-zero, the upper layers assume the processing logic has failed. However, the probe operation was performed earlier without a corresponding remove operation. Since the probe actually allocates resources, failing to perform the remove operation could lead to problems.

To fix this issue, we followed the resource release logic of the xenbus_dev_remove() function by adding a new block fail_remove before the fail_put block. After entering the branch if (err) at line 313, the function will use a goto statement to jump to the fail_remove block, ensuring that the previously acquired resources are correctly released, thus preventing the reference count leak.

This bug was identified by an experimental static analysis tool developed by our team. The tool specializes in analyzing reference count operations and detecting potential issues where resources are not properly managed. In this case, the tool flagged the missing release operation as a potential problem, which led to the development of this patch.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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/0aa9e30b5b4af5dd504801689d6d84c584290a45
• https://git.kernel.org/stable/c/217bdce88b104269b73603b84d0ab4dd04f481bc
• https://git.kernel.org/stable/c/2f977a4c82d35d063f5fe198bbc501c4b1c5ea0e
• https://git.kernel.org/stable/c/3fc0996d2fefe61219375fd650601724b8cf2d30
• https://git.kernel.org/stable/c/804b96f8d0a02fa10b92f28b2e042f9128ed3ffc
• https://git.kernel.org/stable/c/87106169b4ce26f85561f953d13d1fd86d99b612
• https://git.kernel.org/stable/c/afc545da381ba0c651b2658966ac737032676f01
• https://git.kernel.org/stable/c/e8823e6ff313465910edea07581627d85e68d9fd
• https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
• https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html