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

HID: amd_sfh: Fix memory leak in amd_sfh_work

Kmemleak tool detected a memory leak in the amd_sfh driver.

==================== unreferenced object 0xffff88810228ada0 (size 32): comm insmod, pid 3968, jiffies 4295056001 (age 775.792s) hex dump (first 32 bytes): 00 20 73 1f 81 88 ff ff 00 01 00 00 00 00 ad de . s…………. 22 01 00 00 00 00 ad de 01 00 02 00 00 00 00 00 …………… backtrace: [<000000007b4c8799>] kmem_cache_alloc_trace+0x163/0x4f0 [<0000000005326893>] amd_sfh_get_report+0xa4/0x1d0 [amd_sfh] [<000000002a9e5ec4>] amdtp_hid_request+0x62/0x80 [amd_sfh] [<00000000b8a95807>] sensor_hub_get_feature+0x145/0x270 [hid_sensor_hub] [<00000000fda054ee>] hid_sensor_parse_common_attributes+0x215/0x460 [hid_sensor_iio_common] [<0000000021279ecf>] hid_accel_3d_probe+0xff/0x4a0 [hid_sensor_accel_3d] [<00000000915760ce>] platform_probe+0x6a/0xd0 [<0000000060258a1f>] really_probe+0x192/0x620 [<00000000fa812f2d>] driver_probe_device+0x14a/0x1d0 [<000000005e79f7fd>] __device_attach_driver+0xbd/0x110 [<0000000070d15018>] bus_for_each_drv+0xfd/0x160 [<0000000013a3c312>] __device_attach+0x18b/0x220 [<000000008c7b4afc>] device_initial_probe+0x13/0x20 [<00000000e6e99665>] bus_probe_device+0xfe/0x120 [<00000000833fa90b>] device_add+0x6a6/0xe00 [<00000000fa901078>] platform_device_add+0x180/0x380

The fix is to freeing request_list entry once the processed entry is removed from the request_list.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

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/29beadea66a226d744d5ffdcde6b984623053d24
• https://git.kernel.org/stable/c/5ad755fd2b326aa2bc8910b0eb351ee6aece21b1
• https://git.kernel.org/stable/c/29beadea66a226d744d5ffdcde6b984623053d24
• https://git.kernel.org/stable/c/5ad755fd2b326aa2bc8910b0eb351ee6aece21b1