[Kernel] [PATCH OpenHarmony-5.10 14/16] acpi: acpica: fix acpi operand cache leak in dsutils.c

From: Seunghun Han maillist inclusion category: bugfix issue: #I4LRGQ CVE: CVE-2017-13693 Reference: https://lore.kernel.org/all/1503551495-33286-1-git-send-email-kkamagui@gmail... ------------------------------------------------- I found an ACPI cache leak in ACPI early termination and boot continuing case. When early termination is occurred due to malicious ACPI table, Linux kernel terminates ACPI function and continues to boot process. While kernel terminates ACPI function, kmem_cache_destroy() reports Acpi-Operand cache leak. Boot log of ACPI operand cache leak is as follows:

[ 0.585957] ACPI: Added _OSI(Module Device) [ 0.587218] ACPI: Added _OSI(Processor Device) [ 0.588530] ACPI: Added _OSI(3.0 _SCP Extensions) [ 0.589790] ACPI: Added _OSI(Processor Aggregator Device) [ 0.591534] ACPI Error: Illegal I/O port address/length above 64K: C806E00000004002/0x2 (20170303/hwvalid-155) [ 0.594351] ACPI Exception: AE_LIMIT, Unable to initialize fixed events (20170303/evevent-88) [ 0.597858] ACPI: Unable to start the ACPI Interpreter [ 0.599162] ACPI Error: Could not remove SCI handler (20170303/evmisc-281) [ 0.601836] kmem_cache_destroy Acpi-Operand: Slab cache still has objects [ 0.603556] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc5 #26 [ 0.605159] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 0.609177] Call Trace: [ 0.610063] ? dump_stack+0x5c/0x81 [ 0.611118] ? kmem_cache_destroy+0x1aa/0x1c0 [ 0.612632] ? acpi_sleep_proc_init+0x27/0x27 [ 0.613906] ? acpi_os_delete_cache+0xa/0x10 [ 0.617986] ? acpi_ut_delete_caches+0x3f/0x7b [ 0.619293] ? acpi_terminate+0xa/0x14 [ 0.620394] ? acpi_init+0x2af/0x34f [ 0.621616] ? __class_create+0x4c/0x80 [ 0.623412] ? video_setup+0x7f/0x7f [ 0.624585] ? acpi_sleep_proc_init+0x27/0x27 [ 0.625861] ? do_one_initcall+0x4e/0x1a0 [ 0.627513] ? kernel_init_freeable+0x19e/0x21f [ 0.628972] ? rest_init+0x80/0x80 [ 0.630043] ? kernel_init+0xa/0x100 [ 0.631084] ? ret_from_fork+0x25/0x30 [ 0.633343] vgaarb: loaded [ 0.635036] EDAC MC: Ver: 3.0.0 [ 0.638601] PCI: Probing PCI hardware [ 0.639833] PCI host bridge to bus 0000:00 [ 0.641031] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] ... Continue to boot and log is omitted ...

I analyzed this memory leak in detail and found acpi_ds_obj_stack_pop_and_ delete() function miscalculated the top of the stack. acpi_ds_obj_stack_push() function uses walk_state->operand_index for start position of the top, but acpi_ds_obj_stack_pop_and_delete() function considers index 0 for it. Therefore, this causes acpi operand memory leak. This cache leak causes a security threat because an old kernel (<= 4.9) shows memory locations of kernel functions in stack dump. Some malicious users could use this information to neutralize kernel ASLR. I made a patch to fix ACPI operand cache leak. Signed-off-by: Seunghun Han Signed-off-by: Yang Yingliang Reviewed-by: Hanjun Guo Signed-off-by: Yang Yingliang Signed-off-by: Chen Jun Reviewed-by: Xiu Jianfeng Reviewed-by: Hanjun Guo Signed-off-by: Chen Jun Signed-off-by: Zheng Zengkai Signed-off-by: Yu Changchun --- drivers/acpi/acpica/dsutils.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/acpica/dsutils.c b/drivers/acpi/acpica/dsutils.c index fb9ed5e1da89..2bdae8a25e08 100644 --- a/drivers/acpi/acpica/dsutils.c +++ b/drivers/acpi/acpica/dsutils.c @@ -668,6 +668,8 @@ acpi_ds_create_operands(struct acpi_walk_state *walk_state, union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS]; u32 arg_count = 0; u32 index = walk_state->num_operands; + u32 prev_num_operands = walk_state->num_operands; + u32 new_num_operands; u32 i; ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg); @@ -696,6 +698,7 @@ acpi_ds_create_operands(struct acpi_walk_state *walk_state, /* Create the interpreter arguments, in reverse order */ + new_num_operands = index; index--; for (i = 0; i < arg_count; i++) { arg = arguments[index]; @@ -720,7 +723,11 @@ acpi_ds_create_operands(struct acpi_walk_state *walk_state, * pop everything off of the operand stack and delete those * objects */ - acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state); + walk_state->num_operands = i; + acpi_ds_obj_stack_pop_and_delete(new_num_operands, walk_state); + + /* Restore operand count */ + walk_state->num_operands = prev_num_operands; ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index)); return_ACPI_STATUS(status); -- 2.25.1