CKI KWF Bot b38e3d3909 Merge: CVE-2026-64277: Input: synaptics-rmi4 - bound the F3A keymap to the GPIO count
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/8551

JIRA: https://redhat.atlassian.net/browse/RHEL-231453
CVE: CVE-2026-64277

Backported from tree(s): linux

```
Input: synaptics-rmi4 - bound the F3A keymap to the GPIO count

rmi_f3a_initialize() takes the GPIO count from the device query register
(f3a->gpio_count = buf & RMI_F3A_GPIO_COUNT, range 0..127).
rmi_f3a_map_gpios() then allocates gpio_key_map with
min(gpio_count, TRACKSTICK_RANGE_END) == at most 6 entries, but
rmi_f3a_attention() iterates the full gpio_count and dereferences
gpio_key_map[i], and input->keycodemax is set to the full gpio_count
while input->keycode points at the 6-entry allocation.

A device that reports gpio_count > 6 therefore causes an out-of-bounds
read of gpio_key_map[] on every attention interrupt, and out-of-bounds
accesses through the input core's default keymap ioctls: EVIOCGKEYCODE
reads past the buffer (leaking adjacent slab memory to user space) and
EVIOCSKEYCODE writes a caller-controlled value past it, for any process
able to open the evdev node, since input_default_getkeycode() and
input_default_setkeycode() only bound the index against keycodemax.

Size the keymap for the full gpio_count. The mapping loop is unchanged:
it still assigns only the first min(gpio_count, TRACKSTICK_RANGE_END)
entries; the remaining slots stay KEY_RESERVED (devm_kcalloc zero-fills)
and are skipped when reporting.

Fixes: 9e4c596bfd ("Input: synaptics-rmi4 - add support for F3A")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Link: https://patch.msgid.link/20260614-b4-disp-818d6bda-v1-1-cf39a3615085@proton.me
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
(cherry picked from commit 57c10915f2c16c90e0d46ad00876bf39ece40fc2)

```

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
[^footer]: Created 2026-08-06 00:27 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://redhat.atlassian.net/secure/CreateIssueDetails!init.jspa?pid=11779&issuetype=10016&priority=10001&summary=backporter+webhook+issue&components=66291) [^footer]

Approved-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Approved-by: Tony Camuso <tcamuso@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>
2026-08-21 17:22:17 +00:00
2026-08-20 12:21:17 +00:00
2026-08-20 12:22:12 +00:00
2021-08-30 10:50:55 -04:00

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