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From:   Li Zetao <lizetao1@huawei.com>
To:     <robert.moore@intel.com>, <rafael.j.wysocki@intel.com>,
        <lenb@kernel.org>, <lv.zheng@intel.com>,
        <david.e.box@linux.intel.com>
CC:     <lizetao1@huawei.com>, <linux-acpi@vger.kernel.org>,
        <devel@acpica.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] ACPICA: Fix use-after-free in acpi_ut_copy_ipackage_to_ipackage()
Date:   Thu, 1 Dec 2022 16:05:14 +0800
Message-ID: <20221201080514.3015400-1-lizetao1@huawei.com>
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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:
   <TASK>
   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
   ...
   </TASK>

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.

Fixes: 8aa5e56eeb61 ("ACPICA: Utilities: Fix memory leak in acpi_ut_copy_iobject_to_iobject")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
---
 drivers/acpi/acpica/utcopy.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/acpi/acpica/utcopy.c b/drivers/acpi/acpica/utcopy.c
index 400b9e15a709..63c17f420fb8 100644
--- a/drivers/acpi/acpica/utcopy.c
+++ b/drivers/acpi/acpica/utcopy.c
@@ -916,13 +916,6 @@ acpi_ut_copy_ipackage_to_ipackage(union acpi_operand_object *source_obj,
 	status = acpi_ut_walk_package_tree(source_obj, dest_obj,
 					   acpi_ut_copy_ielement_to_ielement,
 					   walk_state);
-	if (ACPI_FAILURE(status)) {
-
-		/* On failure, delete the destination package object */
-
-		acpi_ut_remove_reference(dest_obj);
-	}
-
 	return_ACPI_STATUS(status);
 }
 
-- 
2.31.1