CVE-2022-50331

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

wwan_hwsim: fix possible memory leak in wwan_hwsim_dev_new()

Inject fault while probing module, if device_register() fails, but the refcount of kobject is not decreased to 0, the name allocated in dev_set_name() is leaked. Fix this by calling put_device(), so that name can be freed in callback function kobject_cleanup().

unreferenced object 0xffff88810152ad20 (size 8): comm modprobe, pid 252, jiffies 4294849206 (age 22.713s) hex dump (first 8 bytes): 68 77 73 69 6d 30 00 ff hwsim0.. backtrace: [<000000009c3504ed>] __kmalloc_node_track_caller+0x44/0x1b0 [<00000000c0228a5e>] kvasprintf+0xb5/0x140 [<00000000cff8c21f>] kvasprintf_const+0x55/0x180 [<0000000055a1e073>] kobject_set_name_vargs+0x56/0x150 [<000000000a80b139>] dev_set_name+0xab/0xe0

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/258ad2fe5ede773625adfda88b173f4123e59f45
• https://git.kernel.org/stable/c/50c31fa952309536c6e4461ff815ddccc8dff9d5
• https://git.kernel.org/stable/c/d87973314aba6de80a49f4271dd9be4ddc08e729