Messages in this thread | | | Date | Tue, 01 Sep 2020 10:44:28 +0100 | From | Marc Zyngier <> | Subject | Re: [PATCH v3] HID: core: Sanitize event code and type when mapping input |
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On 2020-08-27 22:05, Marc Zyngier wrote: > When calling into hid_map_usage(), the passed event code is > blindly stored as is, even if it doesn't fit in the associated bitmap. > > This event code can come from a variety of sources, including devices > masquerading as input devices, only a bit more "programmable". > > Instead of taking the event code at face value, check that it actually > fits the corresponding bitmap, and if it doesn't: > - spit out a warning so that we know which device is acting up > - NULLify the bitmap pointer so that we catch unexpected uses > > Code paths that can make use of untrusted inputs can now check > that the mapping was indeed correct and bail out if not. > > Cc: stable@vger.kernel.org > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > * From v2: > - Don't prematurely narrow the event code so that hid_map_usage() > catches illegal values beyond the 16bit limit. > > * From v1: > - Dropped the input.c changes, and turned hid_map_usage() into > the validation primitive. > - Handle mapping failures in hidinput_configure_usage() and > mt_touch_input_mapping() (on top of hid_map_usage_clear() which > was already handled) > > drivers/hid/hid-input.c | 4 ++++ > drivers/hid/hid-multitouch.c | 2 ++ > drivers/mfd/syscon.c | 2 +- > include/linux/hid.h | 42 +++++++++++++++++++++++++----------- > 4 files changed, 36 insertions(+), 14 deletions(-) >
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> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index 7a660411c562..75859e492984 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -108,6 +108,7 @@ static struct syscon *of_syscon_register(struct > device_node *np, bool check_clk) > syscon_config.max_register = resource_size(&res) - reg_io_width; > > regmap = regmap_init_mmio(NULL, base, &syscon_config); > + kfree(syscon_config.name); > if (IS_ERR(regmap)) { > pr_err("regmap init failed\n"); > ret = PTR_ERR(regmap); > @@ -144,7 +145,6 @@ static struct syscon *of_syscon_register(struct > device_node *np, bool check_clk) > regmap_exit(regmap); > err_regmap: > iounmap(base); > - kfree(syscon_config.name); > err_map: > kfree(syscon); > return ERR_PTR(ret);
This hunk is totally unrelated, and is from another fix I was working on at the same time... Sorry for the nois, I'll post v4 (hopefully final) now.
M. -- Jazz is not dead. It just smells funny...
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