Commit 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()") enforced the provided data to be at least the size of the declared buffer in the report descriptor to prevent a buffer overflow.
We only had corner cases of malicious devices exposing the OOM because in most cases, the buffer provided by the transport layer needs to be allocated at probe time and is large enough to handle all the possible reports.
However, the patch from above, which enforces the spec a little bit more introduced both regressions for devices not following the spec (not necesserally malicious), but also a stream of errors for those devices.
Let's revert to the old behavior by giving more information to HID core to be able to decide whether it can or not memset the rest of the buffer to 0 and continue the processing.
Note that the first commit makes an API change, but the callers are relatively limited, so it should be fine on its own. The second patch can't really make the same kind of API change because we have too many callers in various subsystems. We can switch them one by one to the safe approach when needed.
The last 2 patches are small cleanups I initially put together with the 2 first patches, but they can be applied on their own and don't need to be pulled in stable like the first 2.
Cheers, Benjamin
Signed-off-by: Benjamin Tissoires bentiss@kernel.org --- Changes in v2: - added a small blurb explaining the difference between the safe and the non safe version of hid_safe_input_report - Link to v1: https://lore.kernel.org/r/20260415-wip-fix-core-v1-0-ed3c4c823175@kernel.org
--- Benjamin Tissoires (4): HID: pass the buffer size to hid_report_raw_event HID: core: introduce hid_safe_input_report() HID: multitouch: use __free(kfree) to clean up temporary buffers HID: wacom: use __free(kfree) to clean up temporary buffers
drivers/hid/bpf/hid_bpf_dispatch.c | 6 ++-- drivers/hid/hid-core.c | 67 ++++++++++++++++++++++++++++++-------- drivers/hid/hid-gfrm.c | 4 +-- drivers/hid/hid-logitech-hidpp.c | 2 +- drivers/hid/hid-multitouch.c | 18 ++++------ drivers/hid/hid-primax.c | 2 +- drivers/hid/hid-vivaldi-common.c | 2 +- drivers/hid/i2c-hid/i2c-hid-core.c | 7 ++-- drivers/hid/usbhid/hid-core.c | 11 ++++--- drivers/hid/wacom_sys.c | 46 +++++++++----------------- drivers/staging/greybus/hid.c | 2 +- include/linux/hid.h | 6 ++-- include/linux/hid_bpf.h | 14 +++++--- 13 files changed, 109 insertions(+), 78 deletions(-) --- base-commit: 7df6572f1cb381d6b89ceed58e3b076c233c2cd0 change-id: 20260415-wip-fix-core-7d85c8516ed0
Best regards,