CVE-2023-53303

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

net: microchip: vcap api: Fix possible memory leak for vcap_dup_rule()

Inject fault When select CONFIG_VCAP_KUNIT_TEST, the below memory leak occurs. If kzalloc() for duprule succeeds, but the following kmemdup() fails, the duprule, ckf and caf memory will be leaked. So kfree them in the error path.

unreferenced object 0xffff122744c50600 (size 192): comm kunit_try_catch, pid 346, jiffies 4294896122 (age 911.812s) hex dump (first 32 bytes): 10 27 00 00 04 00 00 00 1e 00 00 00 2c 01 00 00 ………..,… 00 00 00 00 00 00 00 00 18 06 c5 44 27 12 ff ff ………..D… backtrace: [<00000000394b0db8>] __kmem_cache_alloc_node+0x274/0x2f8 [<0000000001bedc67>] kmalloc_trace+0x38/0x88 [<00000000b0612f98>] vcap_dup_rule+0x50/0x460 [<000000005d2d3aca>] vcap_add_rule+0x8cc/0x1038 [<00000000eef9d0f8>] test_vcap_xn_rule_creator.constprop.0.isra.0+0x238/0x494 [<00000000cbda607b>] vcap_api_rule_remove_in_front_test+0x1ac/0x698 [<00000000c8766299>] kunit_try_run_case+0xe0/0x20c [<00000000c4fe9186>] kunit_generic_run_threadfn_adapter+0x50/0x94 [<00000000f6864acf>] kthread+0x2e8/0x374 [<0000000022e639b3>] ret_from_fork+0x10/0x20

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/281f65d29d6da1a9b6907fb0b145aaf34f4e4822
• https://git.kernel.org/stable/c/a26ba60413b2c8f95daf0ee0152cf82abd7bfbe4