CVE-2021-47499

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

iio: accel: kxcjk-1013: Fix possible memory leak in probe and remove

When ACPI type is ACPI_SMO8500, the data->dready_trig will not be set, the memory allocated by iio_triggered_buffer_setup() will not be freed, and cause memory leak as follows:

unreferenced object 0xffff888009551400 (size 512): comm i2c-SMO8500-125, pid 911, jiffies 4294911787 (age 83.852s) hex dump (first 32 bytes): 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. 00 00 00 00 00 00 00 00 20 e2 e5 c0 ff ff ff ff …….. ……. backtrace: [<0000000041ce75ee>] kmem_cache_alloc_trace+0x16d/0x360 [<000000000aeb17b0>] iio_kfifo_allocate+0x41/0x130 [kfifo_buf] [<000000004b40c1f5>] iio_triggered_buffer_setup_ext+0x2c/0x210 [industrialio_triggered_buffer] [<000000004375b15f>] kxcjk1013_probe+0x10c3/0x1d81 [kxcjk_1013]

Fix it by remove data->dready_trig condition in probe and remove.

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/14508fe13b1c578b3d2ba574f1d48b351975860c
• https://git.kernel.org/stable/c/3899700ddacbf7aaafadf44464fff3ff0d4e3307
• https://git.kernel.org/stable/c/60a55b9d91ba99eb8cf015bc46dc2de05e168a15
• https://git.kernel.org/stable/c/70c9774e180d151abaab358108e3510a8e615215
• https://git.kernel.org/stable/c/8c163a14277115ca962103910ab4cce55e862ffb
• https://git.kernel.org/stable/c/8c1d43f3a3fc7184c42d7398bdf59a2a2903e4fc
• https://git.kernel.org/stable/c/a3730f74159ad00a28960c0efe2a931fe6fe6b45
• https://git.kernel.org/stable/c/ee86d0bad80bdcd11a87e188a596727f41b62320
• https://git.kernel.org/stable/c/14508fe13b1c578b3d2ba574f1d48b351975860c
• https://git.kernel.org/stable/c/3899700ddacbf7aaafadf44464fff3ff0d4e3307
• https://git.kernel.org/stable/c/60a55b9d91ba99eb8cf015bc46dc2de05e168a15
• https://git.kernel.org/stable/c/70c9774e180d151abaab358108e3510a8e615215
• https://git.kernel.org/stable/c/8c163a14277115ca962103910ab4cce55e862ffb
• https://git.kernel.org/stable/c/8c1d43f3a3fc7184c42d7398bdf59a2a2903e4fc
• https://git.kernel.org/stable/c/a3730f74159ad00a28960c0efe2a931fe6fe6b45
• https://git.kernel.org/stable/c/ee86d0bad80bdcd11a87e188a596727f41b62320