From: Tamir Duberstein <tamird@xxxxxxxxxx> ACPICA commit 770653e3ba67c30a629ca7d12e352d83c2541b1e Before this change we see the following UBSAN stack trace in Fuchsia: #0 0x000021e4213b3302 in acpi_ds_init_aml_walk(struct acpi_walk_state*, union acpi_parse_object*, struct acpi_namespace_node*, u8*, u32, struct acpi_evaluate_info*, u8) ../../third_party/acpica/source/components/dispatcher/dswstate.c:682 <platform-bus-x86.so>+0x233302 #1.2 0x000020d0f660777f in ubsan_get_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:41 <libclang_rt.asan.so>+0x3d77f #1.1 0x000020d0f660777f in maybe_print_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:51 <libclang_rt.asan.so>+0x3d77f #1 0x000020d0f660777f in ~scoped_report() compiler-rt/lib/ubsan/ubsan_diag.cpp:387 <libclang_rt.asan.so>+0x3d77f #2 0x000020d0f660b96d in handlepointer_overflow_impl() compiler-rt/lib/ubsan/ubsan_handlers.cpp:809 <libclang_rt.asan.so>+0x4196d #3 0x000020d0f660b50d in compiler-rt/lib/ubsan/ubsan_handlers.cpp:815 <libclang_rt.asan.so>+0x4150d #4 0x000021e4213b3302 in acpi_ds_init_aml_walk(struct acpi_walk_state*, union acpi_parse_object*, struct acpi_namespace_node*, u8*, u32, struct acpi_evaluate_info*, u8) ../../third_party/acpica/source/components/dispatcher/dswstate.c:682 <platform-bus-x86.so>+0x233302 #5 0x000021e4213e2369 in acpi_ds_call_control_method(struct acpi_thread_state*, struct acpi_walk_state*, union acpi_parse_object*) ../../third_party/acpica/source/components/dispatcher/dsmethod.c:605 <platform-bus-x86.so>+0x262369 #6 0x000021e421437fac in acpi_ps_parse_aml(struct acpi_walk_state*) ../../third_party/acpica/source/components/parser/psparse.c:550 <platform-bus-x86.so>+0x2b7fac #7 0x000021e4214464d2 in acpi_ps_execute_method(struct acpi_evaluate_info*) ../../third_party/acpica/source/components/parser/psxface.c:244 <platform-bus-x86.so>+0x2c64d2 #8 0x000021e4213aa052 in acpi_ns_evaluate(struct acpi_evaluate_info*) ../../third_party/acpica/source/components/namespace/nseval.c:250 <platform-bus-x86.so>+0x22a052 #9 0x000021e421413dd8 in acpi_ns_init_one_device(acpi_handle, u32, void*, void**) ../../third_party/acpica/source/components/namespace/nsinit.c:735 <platform-bus-x86.so>+0x293dd8 #10 0x000021e421429e98 in acpi_ns_walk_namespace(acpi_object_type, acpi_handle, u32, u32, acpi_walk_callback, acpi_walk_callback, void*, void**) ../../third_party/acpica/source/components/namespace/nswalk.c:298 <platform-bus-x86.so>+0x2a9e98 #11 0x000021e4214131ac in acpi_ns_initialize_devices(u32) ../../third_party/acpica/source/components/namespace/nsinit.c:268 <platform-bus-x86.so>+0x2931ac #12 0x000021e42147c40d in acpi_initialize_objects(u32) ../../third_party/acpica/source/components/utilities/utxfinit.c:304 <platform-bus-x86.so>+0x2fc40d #13 0x000021e42126d603 in acpi::acpi_impl::initialize_acpi(acpi::acpi_impl*) ../../src/devices/board/lib/acpi/acpi-impl.cc:224 <platform-bus-x86.so>+0xed603 Add a simple check that avoids incrementing a pointer by zero, but otherwise behaves as before. Note that our findings are against ACPICA 20221020, but the same code exists on master. Link: https://github.com/acpica/acpica/commit/770653e3 Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- drivers/acpi/acpica/dswstate.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/acpica/dswstate.c b/drivers/acpi/acpica/dswstate.c index 95af370a7dce..d3841ded3a81 100644 --- a/drivers/acpi/acpica/dswstate.c +++ b/drivers/acpi/acpica/dswstate.c @@ -576,9 +576,14 @@ acpi_ds_init_aml_walk(struct acpi_walk_state *walk_state, ACPI_FUNCTION_TRACE(ds_init_aml_walk); walk_state->parser_state.aml = - walk_state->parser_state.aml_start = aml_start; - walk_state->parser_state.aml_end = - walk_state->parser_state.pkg_end = aml_start + aml_length; + walk_state->parser_state.aml_start = + walk_state->parser_state.aml_end = + walk_state->parser_state.pkg_end = aml_start; + /* Avoid undefined behavior: applying zero offset to null pointer */ + if (aml_length != 0) { + walk_state->parser_state.aml_end += aml_length; + walk_state->parser_state.pkg_end += aml_length; + } /* The next_op of the next_walk will be the beginning of the method */ -- 2.35.3
