CVE-2022-50423

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

ACPICA: Fix use-after-free in acpi_ut_copy_ipackage_to_ipackage()

There is an use-after-free reported by KASAN:

BUG: KASAN: use-after-free in acpi_ut_remove_reference+0x3b/0x82 Read of size 1 at addr ffff888112afc460 by task modprobe/2111 CPU: 0 PID: 2111 Comm: modprobe Not tainted 6.1.0-rc7-dirty Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), Call Trace: kasan_report+0xae/0xe0 acpi_ut_remove_reference+0x3b/0x82 acpi_ut_copy_iobject_to_iobject+0x3be/0x3d5 acpi_ds_store_object_to_local+0x15d/0x3a0 acpi_ex_store+0x78d/0x7fd acpi_ex_opcode_1A_1T_1R+0xbe4/0xf9b acpi_ps_parse_aml+0x217/0x8d5 …

The root cause of the problem is that the acpi_operand_object is freed when acpi_ut_walk_package_tree() fails in acpi_ut_copy_ipackage_to_ipackage(), lead to repeated release in acpi_ut_copy_iobject_to_iobject(). The problem was introduced by 8aa5e56eeb61 commit, this commit is to fix memory leak in acpi_ut_copy_iobject_to_iobject(), repeatedly adding remove operation, lead to acpi_operand_object used after free.

Fix it by removing acpi_ut_remove_reference() in acpi_ut_copy_ipackage_to_ipackage(). acpi_ut_copy_ipackage_to_ipackage() is called to copy an internal package object into another internal package object, when it fails, the memory of acpi_operand_object should be freed by the caller.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/01f2c2052ea50fb9a8ce12e4e83aed0267934ef0
• https://git.kernel.org/stable/c/02617006b5a46f2ea55ac61f5693c7afd7bf9276
• https://git.kernel.org/stable/c/02f237423c9c6a18e062de2d474f85d5659e4eb9
• https://git.kernel.org/stable/c/133462d35dae95edb944af86b986d4c9dec59bd1
• https://git.kernel.org/stable/c/470188b09e92d83c5a997f25f0e8fb8cd2bc3469
• https://git.kernel.org/stable/c/6fde666278f91b85d71545a0ebbf41d8d7af8074
• https://git.kernel.org/stable/c/c9125b643fc51b8e662f2f614096ceb45a0adbc3
• https://git.kernel.org/stable/c/dfdde4d5138bc023897033a5ac653a84e94805be
• https://git.kernel.org/stable/c/f51b2235e4f320edc839c3e5cb0d1f8a6e8657c6