CVE-2022-49830

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

drm/drv: Fix potential memory leak in drm_dev_init()

drm_dev_init() will add drm_dev_init_release() as a callback. When drmm_add_action() failed, the release function wont be added. As the result, the ref cnt added by device_get() in drm_dev_init() wont be put by drm_dev_init_release(), which leads to the memleak. Use drmm_add_action_or_reset() instead of drmm_add_action() to prevent memleak.

unreferenced object 0xffff88810bc0c800 (size 2048): comm modprobe, pid 8322, jiffies 4305809845 (age 15.292s) hex dump (first 32 bytes): e8 cc c0 0b 81 88 ff ff ff ff ff ff 00 00 00 00 ……………. 20 24 3c 0c 81 88 ff ff 18 c8 c0 0b 81 88 ff ff $<…………. backtrace: [<000000007251f72d>] __kmalloc+0x4b/0x1c0 [<0000000045f21f26>] platform_device_alloc+0x2d/0xe0 [<000000004452a479>] platform_device_register_full+0x24/0x1c0 [<0000000089f4ea61>] 0xffffffffa0736051 [<00000000235b2441>] do_one_initcall+0x7a/0x380 [<0000000001a4a177>] do_init_module+0x5c/0x230 [<000000002bf8a8e2>] load_module+0x227d/0x2420 [<00000000637d6d0a>] __do_sys_finit_module+0xd5/0x140 [<00000000c99fc324>] do_syscall_64+0x3f/0x90 [<000000004d85aa77>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

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/07e56de8766fe5be67252596244b84ac0ec0de91
• https://git.kernel.org/stable/c/bd8d1335e6e70a396094ef98913b513140c0b86b
• https://git.kernel.org/stable/c/c47a823ea186263ab69cfb665327b7f72cb5e779
• https://git.kernel.org/stable/c/ff963634f7b2e0dc011349abb3fb81a0d074f443