From: Jorge Lopez jorge.lopez2@hp.com
[ Upstream commit dc6a6ab58379f25bf991d8e4a13b001ed806e881 ]
WMI queries fail on some devices where the ACPI method HWMC unconditionally attempts to create Fields beyond the buffer if the buffer is too small, this breaks essential features such as power profiles:
CreateByteField (Arg1, 0x10, D008) CreateByteField (Arg1, 0x11, D009) CreateByteField (Arg1, 0x12, D010) CreateDWordField (Arg1, 0x10, D032) CreateField (Arg1, 0x80, 0x0400, D128)
In cases where args->data had zero length, ACPI BIOS Error (bug): AE_AML_BUFFER_LIMIT, Field [D008] at bit offset/length 128/8 exceeds size of target Buffer (128 bits) (20211217/dsopcode-198) was obtained.
ACPI BIOS Error (bug): AE_AML_BUFFER_LIMIT, Field [D009] at bit offset/length 136/8 exceeds size of target Buffer (136bits) (20211217/dsopcode-198)
The original code created a buffer size of 128 bytes regardless if the WMI call required a smaller buffer or not. This particular behavior occurs in older BIOS and reproduced in OMEN laptops. Newer BIOS handles buffer sizes properly and meets the latest specification requirements. This is the reason why testing with a dynamically allocated buffer did not uncover any failures with the test systems at hand.
This patch was tested on several OMEN, Elite, and Zbooks. It was confirmed the patch resolves HPWMI_FAN GET/SET calls in an OMEN Laptop 15-ek0xxx. No problems were reported when testing on several Elite and Zbooks notebooks.
Fixes: 4b4967cbd268 ("platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated") Signed-off-by: Jorge Lopez jorge.lopez2@hp.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Link: https://lore.kernel.org/r/20220608212923.8585-2-jorge.lopez2@hp.com Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/hp-wmi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c index 0e9a25b56e0e..d3540dd62d06 100644 --- a/drivers/platform/x86/hp-wmi.c +++ b/drivers/platform/x86/hp-wmi.c @@ -290,14 +290,16 @@ static int hp_wmi_perform_query(int query, enum hp_wmi_command command, struct bios_return *bios_return; union acpi_object *obj = NULL; struct bios_args *args = NULL; - int mid, actual_outsize, ret; + int mid, actual_insize, actual_outsize; size_t bios_args_size; + int ret;
mid = encode_outsize_for_pvsz(outsize); if (WARN_ON(mid < 0)) return mid;
- bios_args_size = struct_size(args, data, insize); + actual_insize = max(insize, 128); + bios_args_size = struct_size(args, data, actual_insize); args = kmalloc(bios_args_size, GFP_KERNEL); if (!args) return -ENOMEM;