kernel/linux.git/drivers/hid, branch v5.15.220

HID: input: read battery capacity from its actual report offset

2026-09-02T12:27:28+00:00

[ Upstream commit d07644524b6511b622ee7b0e2e68c9ee43d522a4 ] hidinput_query_battery_capacity() assumes the state-of-charge value is the first byte following the report ID (buf[1]) and ignores where the battery field actually sits within the report. An Apple Magic Trackpad 2 precedes the AbsoluteStateOfCharge byte with a byte of status flags in its battery reports, so this query returns the flags byte instead of the charge level. The device happens to make that easy to observe, because it exposes the same cell twice: its report descriptor declares AbsoluteStateOfCharge in two reports (0x90 and 0x9b), so hidinput_setup_battery() registers two power supplies. Only the first one is refreshed by hid-magicmouse -- it uses hid_get_battery(), which returns the first battery of the list -- and that refresh goes through the report event path, which parses the field correctly. Nothing ever reports the second one, so every read of its capacity takes the query path above. On a USB-C Magic Trackpad over USB, on an unpatched 7.1.5: hid--battery-144 = 100% (Charging) <- report event path hid--battery-155 = 3% (Discharging) <- query path Both are the same physical battery. A raw HIDIOCGINPUT of the two reports at that same moment: report 0x90 -> [90 03 64] report 0x9b -> [9b 03 64 64 00 00 10 00 00 00 00 00 00 00] ^flags ^SoC = 0x64 = 100% The device answers correctly in both cases; only the offset the kernel reads the capacity from is wrong. 0x03 is the flags byte (present, charging), reported as "3%". Bluetooth takes the same query path for its capacity, where the trackpad reported a bogus near-constant ~4% -- 0b100, the FullyCharged flag -- regardless of the real charge. Store the battery field's offset within the report at setup time and use it when querying, so the capacity is read from its real position. The report event path already parses the field correctly through the HID core; only the explicit GET_REPORT query was wrong. Devices whose capacity field is the first field in the report have a report_offset of 0 and are unaffected (buf[1 + 0] == buf[1]). Fixes: 581c4484769e ("HID: input: map digitizer battery usage") Cc: stable@vger.kernel.org Signed-off-by: Jose Villaseñor Montfort Reviewed-by: Alec Hall Signed-off-by: Jiri Kosina [ Adapted `bat->report_offset` and other `struct hid_battery` accessors to the flat `dev->battery_*` fields on `struct hid_device` and replaced `__free(kfree)` with manual `kfree(buf)` calls. ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: fix stack-use-after-return write in I2C read race

2026-09-02T12:27:27+00:00

[ Upstream commit bf3e39df3a397fd82967a31d17c4e02c7feab221 ] ft260_i2c_read() points dev->read_buf at a caller-supplied buffer (often an on-stack variable), arms a completion and waits up to five seconds for the device to return the data. The HID input callback ft260_raw_event() runs in the input/IRQ path, independent of the dev->lock mutex held by the read path, and copies the device-supplied payload into dev->read_buf after a plain NULL check. These two paths share read_buf, read_idx and read_len with no serialization. If the device delays its response until the read times out, ft260_i2c_read() resets the controller, clears read_buf and returns, unwinding the stack frame the buffer lived in. A response that arrives at that moment lets ft260_raw_event() pass the NULL check and then memcpy() the device-controlled payload into the now-freed stack location, a bounded but attacker-influenced stack-use-after-return write triggerable by malicious or malfunctioning hardware. Add a dedicated spinlock that serializes every access to read_buf, read_idx and read_len. ft260_raw_event() now holds it across the NULL check, the memcpy and the index update, while the read path takes it when arming and when clearing the buffer, so the teardown can no longer slip between the check and the copy. Fixes: 6a82582d9fa4 ("HID: ft260: add usb hid to i2c host bridge driver") Cc: stable@vger.kernel.org Signed-off-by: Raman Varabets Reviewed-by: Michael Zaidman Signed-off-by: Jiri Kosina [ de-indented one tab and renamed `rd_len` to `len` since the chunking loop in `ft260_i2c_read()` is absent. ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: validate i2c input report length

2026-09-02T12:27:27+00:00

[ Upstream commit 80c4bbb2b38513e9c3d84805fa61a0ee16d79c45 ] Add two checks to ft260_raw_event() to prevent out-of-bounds reads from malicious or malfunctioning devices: First, reject reports shorter than the 2-byte header (report ID + length fields). Without this, even accessing xfer->length on a 1-byte report is an OOB read. Second, validate xfer->length against the actual data capacity of the received HID report. Each I2C data report ID (0xD0 through 0xDE) defines a different report size in the HID descriptor, so the available payload varies per report. A corrupted length field could cause memcpy to read beyond the report buffer. Reported-by: Sebastián Josué Alba Vives Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina Stable-dep-of: bf3e39df3a39 ("HID: ft260: fix stack-use-after-return write in I2C read race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: missed NACK from busy device

2026-09-02T12:27:27+00:00

[ Upstream commit 5afac727defa0b2a3dffb2abd5fb5f594b98d217 ] When writing into a slow device like an EEPROM chip, the controller may exit the busy state before the device releases the bus. In this case, the ft260_xfer_status returns success before the data transfer completion. The patch fixes it by returning from the ft260_xfer_status() with the "-EAGAIN" on both controller and bus busy status when appropriate. It does not apply to the i2c combined transactions when after the write IO, the controller keeps the bus busy until the read IO and then between reading IOs to ensure an atomic operation. Co-developed-by: Germain Hebert Signed-off-by: Germain Hebert Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina Stable-dep-of: bf3e39df3a39 ("HID: ft260: fix stack-use-after-return write in I2C read race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: wake up device from power saving mode

2026-09-02T12:27:27+00:00

[ Upstream commit 4b3da6853a619a952e8caf2e8393264dd42ffa27 ] The FT260 can enter a power saving mode after being idle for longer than 5 seconds. When being woken up from power saving mode by an I2C write request, a possible NACK is not correctly reported by the controller. As a workaround, the driver will issue an I2C status report two times in ft260_xfer_status() after the chip has been idle for more than 5s. Co-developed-by: Enrik Berkhan Signed-off-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina Stable-dep-of: bf3e39df3a39 ("HID: ft260: fix stack-use-after-return write in I2C read race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: skip unexpected HID input reports

2026-09-02T12:27:27+00:00

[ Upstream commit b7121e3c04440cc2af9cabbabb24efd23741294a ] The FT260 is not supposed to generate unexpected HID reports. However, in theory, the unsolicited HID Input reports can be issued by a specially crafted malicious USB device masquerading as FT260 when the attacker has physical access to the USB port. In this case, the read_buf pointer points to the final data portion of the previous I2C Read transfer, and the memcpy invoked in the ft260_raw_event() will try copying the content of the unexpected report into the wrong location. This commit sets the Read buffer pointer to NULL on the I2C Read transaction completion and checks it in the ft260_raw_event() to detect and skip the unsolicited Input report. Reported-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina Stable-dep-of: bf3e39df3a39 ("HID: ft260: fix stack-use-after-return write in I2C read race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: improve i2c large reads performance

2026-09-02T12:27:27+00:00

[ Upstream commit 54410c14800ad652c77e5c6fc5c17baad6e42cb6 ] The patch increases the read buffer size to 180 bytes. It reduces the number of ft260_i2c_read() calls by three, improving the big reads performance. $ sudo i2ctransfer -y -f 13 w2@0x51 0x0 0x0 r180 Before: [ +4.071878] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2 [ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.001097] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000175] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000004] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 60 flag 0x3 [ +0.008579] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000208] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 120 rlen 60 flag 0x0 [ +0.008794] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000181] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 60 rlen 60 flag 0x4 [ +0.008817] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000223] ft260_xfer_status: bus_status 0x20, clock 100 After: [ +11.611642] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2 [ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.008001] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 180 flag 0x7 [ +0.008994] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.007987] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.007992] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000206] ft260_xfer_status: bus_status 0x20, clock 100 Suggested-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina Stable-dep-of: bf3e39df3a39 ("HID: ft260: fix stack-use-after-return write in I2C read race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: improve i2c write performance

2026-09-02T12:27:27+00:00

[ Upstream commit 6fca5e3f5574ca1bd5bade5737848c816f924c6a ] The patch improves the I2C write performance by 20 - 30 percent by revising the sleep time in the ft260_hid_output_report_check_status() in the following ways: 1. Reduce the wait time and start to poll earlier. Sending a large amount of data at a low I2C clock rate saturates the internal FT260 buffer and causes hiccups in status readiness, as shown below in the log fragment. Aligning the status check wait time to the worst case significantly reduces the write performance. [Oct22 10:28] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.005296] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.013460] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003244] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000190] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.015324] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003491] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000202] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.016047] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.002768] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000150] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.011389] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003467] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000191] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000172] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000131] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000241] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000233] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000190] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000196] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.011314] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003334] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000227] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000204] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000198] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000147] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.011060] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 Before: $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 40510 80 256 8 32 After: $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 52584 80 256 8 32 2. Do not sleep if the estimated I2C transfer time is below 2 ms since the first xfer status query frequently takes around 1.5 ms, and the following status queries take about 200us on average. So we usually return from the routine after the first 1 - 3 status checks. [Oct22 11:14] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.004270] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.013889] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.000856] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000138] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.013352] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.001501] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000177] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.014477] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.001377] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000233] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000191] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.013197] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 Before: $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 28826 73 256 16 16 After: $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 45138 73 256 16 16 Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne Signed-off-by: Jiri Kosina Stable-dep-of: bf3e39df3a39 ("HID: ft260: fix stack-use-after-return write in I2C read race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: ft260: fix i2c probing for hwmon devices

2026-09-02T12:27:27+00:00

[ Upstream commit a94f61e63f337d95001e1a976ab701100fa1d666 ] The below scenario causes the kernel NULL pointer dereference failure: 1. sudo insmod hid-ft260.ko 2. sudo modprobe lm75 3. unplug USB hid-ft260 4. plug USB hid-ft260 [ +0.000006] Call Trace: [ +0.000004] __i2c_smbus_xfer.part.0+0xd1/0x310 [ +0.000007] ? ft260_smbus_write+0x140/0x140 [hid_ft260] [ +0.000005] __i2c_smbus_xfer+0x2b/0x80 [ +0.000004] i2c_smbus_xfer+0x61/0xf0 [ +0.000005] i2c_default_probe+0xf9/0x130 [ +0.000004] i2c_detect_address+0x84/0x160 [ +0.000004] ? kmem_cache_alloc_trace+0xf6/0x200 [ +0.000009] ? i2c_detect.isra.0+0x69/0x130 [ +0.000005] i2c_detect.isra.0+0xbf/0x130 [ +0.000004] ? __process_new_driver+0x30/0x30 [ +0.000004] __process_new_adapter+0x18/0x20 [ +0.000004] bus_for_each_drv+0x84/0xd0 [ +0.000003] i2c_register_adapter+0x1e4/0x400 [ +0.000005] i2c_add_adapter+0x5c/0x80 [ +0.000004] ft260_probe.cold+0x222/0x2e2 [hid_ft260] [ +0.000006] hid_device_probe+0x10e/0x170 [hid] [ +0.000009] really_probe+0xff/0x460 [ +0.000004] driver_probe_device+0xe9/0x160 [ +0.000003] __device_attach_driver+0x71/0xd0 [ +0.000004] ? driver_allows_async_probing+0x50/0x50 [ +0.000004] bus_for_each_drv+0x84/0xd0 [ +0.000002] __device_attach+0xde/0x1e0 [ +0.000004] device_initial_probe+0x13/0x20 [ +0.000004] bus_probe_device+0x8f/0xa0 [ +0.000003] device_add+0x333/0x5f0 It happened when i2c core probed for the devices associated with the lm75 driver by invoking 2c_detect()-->..-->ft260_smbus_write() from within the ft260_probe before setting the adapter data with i2c_set_adapdata(). Moving the i2c_set_adapdata() before i2c_add_adapter() fixed the failure. Signed-off-by: Michael Zaidman Signed-off-by: Germain Hebert Signed-off-by: Jiri Kosina Stable-dep-of: bf3e39df3a39 ("HID: ft260: fix stack-use-after-return write in I2C read race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

HID: uclogic: fix use-after-free of inrange_timer on remove

2026-09-02T12:27:27+00:00

[ Upstream commit 506fd50a9027340f0e9dcc587d10ccb03312dba6 ] uclogic_remove() cancels the pen in-range timer and then stops the device: timer_delete_sync(&drvdata->inrange_timer); hid_hw_stop(hdev); timer_delete_sync() only guarantees the timer is idle at that instant. uclogic_raw_event_pen() keeps delivering pen reports until hid_hw_stop() stops the transport several lines later, and every report with pen->inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE re-arms the timer: mod_timer(&drvdata->inrange_timer, jiffies + msecs_to_jiffies(100)); A report landing between the timer_delete_sync() call and the transport teardown in hid_hw_stop() re-arms inrange_timer after it was cancelled. uclogic_remove() then returns and the devm drvdata is freed, while hid_hw_stop() has already freed the input device drvdata->pen_input points at, so when the timer fires ~100 ms later uclogic_inrange_timeout() dereferences freed memory -- a use-after-free in timer-softirq context. Swapping the two calls is not a fix: stopping the device first frees drvdata->pen_input via hidinput_disconnect() while the timer may still be pending, so a timer already armed before removal fires on the freed input device in the window before timer_delete_sync() runs. Use timer_shutdown_sync() before hid_hw_stop() instead. It cancels the timer, waits for a running callback while pen_input is still valid, and prevents any further re-arming -- a later mod_timer() from an in-flight report is silently ignored -- so the timer is provably dead before hid_hw_stop() frees the inputs. This is the ordering the timer core documents for this "timer re-armed from another path" teardown case. Fixes: 01309e29eb95 ("HID: uclogic: Support in-range reporting emulation") Cc: stable@vger.kernel.org Signed-off-by: Ibrahim Hashimov Assisted-by: AuditCode-AI:2026.07 Signed-off-by: Jiri Kosina [ changed timer_delete_sync() to del_timer_sync() in the removed line to match the pre-rename API on this branch ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman