coresight: Fix memory leak in acpi_buffer->pointer

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: coresight: Fix memory leak in acpi_buffer->pointer There are memory leaks reported by kmemleak: ... unreferenced object 0xffff00213c141000 (size 1024): comm "systemd-udevd", pid 2123, jiffies 4294909467 (age 6062.160s) hex dump (first 32 bytes): 04 00 00 00 02 00 00 00 18 10 14 3c 21 00 ff ff ...........<!... 00 00 00 00 00 00 00 00 03 00 00 00 10 00 00 00 ................ backtrace: [<000000004b7c9001>] __kmem_cache_alloc_node+0x2f8/0x348 [<00000000b0fc7ceb>] __kmalloc+0x58/0x108 [<0000000064ff4695>] acpi_os_allocate+0x2c/0x68 [<000000007d57d116>] acpi_ut_initialize_buffer+0x54/0xe0 [<0000000024583908>] acpi_evaluate_object+0x388/0x438 [<0000000017b2e72b>] acpi_evaluate_object_typed+0xe8/0x240 [<000000005df0eac2>] coresight_get_platform_data+0x1b4/0x988 [coresight] ... The ACPI buffer memory (buf.pointer) should be freed. But the buffer is also used after returning from acpi_get_dsd_graph(). Move the temporary variables buf to acpi_coresight_parse_graph(), and free it before the function return to prevent memory leak.

References

• https://git.kernel.org/stable/c/d1b60e7c9fee34eaedf1fc4e0471f75b33f83a4a
• https://git.kernel.org/stable/c/1a9e02673e2550f5612099e64e8761f0c8fc0f50