{"id":"CVE-2021-47097","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nInput: elantech - fix stack out of bound access in elantech_change_report_id()\n\nThe array param[] in elantech_change_report_id() must be at least 3\nbytes, because elantech_read_reg_params() is calling ps2_command() with\nPSMOUSE_CMD_GETINFO, that is going to access 3 bytes from param[], but\nit's defined in the stack as an array of 2 bytes, therefore we have a\npotential stack out-of-bounds access here, also confirmed by KASAN:\n\n[    6.512374] BUG: KASAN: stack-out-of-bounds in __ps2_command+0x372/0x7e0\n[    6.512397] Read of size 1 at addr ffff8881024d77c2 by task kworker/2:1/118\n\n[    6.512416] CPU: 2 PID: 118 Comm: kworker/2:1 Not tainted 5.13.0-22-generic #22+arighi20211110\n[    6.512428] Hardware name: LENOVO 20T8000QGE/20T8000QGE, BIOS R1AET32W (1.08 ) 08/14/2020\n[    6.512436] Workqueue: events_long serio_handle_event\n[    6.512453] Call Trace:\n[    6.512462]  show_stack+0x52/0x58\n[    6.512474]  dump_stack+0xa1/0xd3\n[    6.512487]  print_address_description.constprop.0+0x1d/0x140\n[    6.512502]  ? __ps2_command+0x372/0x7e0\n[    6.512516]  __kasan_report.cold+0x7d/0x112\n[    6.512527]  ? _raw_write_lock_irq+0x20/0xd0\n[    6.512539]  ? __ps2_command+0x372/0x7e0\n[    6.512552]  kasan_report+0x3c/0x50\n[    6.512564]  __asan_load1+0x6a/0x70\n[    6.512575]  __ps2_command+0x372/0x7e0\n[    6.512589]  ? ps2_drain+0x240/0x240\n[    6.512601]  ? dev_printk_emit+0xa2/0xd3\n[    6.512612]  ? dev_vprintk_emit+0xc5/0xc5\n[    6.512621]  ? __kasan_check_write+0x14/0x20\n[    6.512634]  ? mutex_lock+0x8f/0xe0\n[    6.512643]  ? __mutex_lock_slowpath+0x20/0x20\n[    6.512655]  ps2_command+0x52/0x90\n[    6.512670]  elantech_ps2_command+0x4f/0xc0 [psmouse]\n[    6.512734]  elantech_change_report_id+0x1e6/0x256 [psmouse]\n[    6.512799]  ? elantech_report_trackpoint.constprop.0.cold+0xd/0xd [psmouse]\n[    6.512863]  ? ps2_command+0x7f/0x90\n[    6.512877]  elantech_query_info.cold+0x6bd/0x9ed [psmouse]\n[    6.512943]  ? elantech_setup_ps2+0x460/0x460 [psmouse]\n[    6.513005]  ? psmouse_reset+0x69/0xb0 [psmouse]\n[    6.513064]  ? psmouse_attr_set_helper+0x2a0/0x2a0 [psmouse]\n[    6.513122]  ? phys_pmd_init+0x30e/0x521\n[    6.513137]  elantech_init+0x8a/0x200 [psmouse]\n[    6.513200]  ? elantech_init_ps2+0xf0/0xf0 [psmouse]\n[    6.513249]  ? elantech_query_info+0x440/0x440 [psmouse]\n[    6.513296]  ? synaptics_send_cmd+0x60/0x60 [psmouse]\n[    6.513342]  ? elantech_query_info+0x440/0x440 [psmouse]\n[    6.513388]  ? psmouse_try_protocol+0x11e/0x170 [psmouse]\n[    6.513432]  psmouse_extensions+0x65d/0x6e0 [psmouse]\n[    6.513476]  ? psmouse_try_protocol+0x170/0x170 [psmouse]\n[    6.513519]  ? mutex_unlock+0x22/0x40\n[    6.513526]  ? ps2_command+0x7f/0x90\n[    6.513536]  ? psmouse_probe+0xa3/0xf0 [psmouse]\n[    6.513580]  psmouse_switch_protocol+0x27d/0x2e0 [psmouse]\n[    6.513624]  psmouse_connect+0x272/0x530 [psmouse]\n[    6.513669]  serio_driver_probe+0x55/0x70\n[    6.513679]  really_probe+0x190/0x720\n[    6.513689]  driver_probe_device+0x160/0x1f0\n[    6.513697]  device_driver_attach+0x119/0x130\n[    6.513705]  ? device_driver_attach+0x130/0x130\n[    6.513713]  __driver_attach+0xe7/0x1a0\n[    6.513720]  ? device_driver_attach+0x130/0x130\n[    6.513728]  bus_for_each_dev+0xfb/0x150\n[    6.513738]  ? subsys_dev_iter_exit+0x10/0x10\n[    6.513748]  ? _raw_write_unlock_bh+0x30/0x30\n[    6.513757]  driver_attach+0x2d/0x40\n[    6.513764]  serio_handle_event+0x199/0x3d0\n[    6.513775]  process_one_work+0x471/0x740\n[    6.513785]  worker_thread+0x2d2/0x790\n[    6.513794]  ? process_one_work+0x740/0x740\n[    6.513802]  kthread+0x1b4/0x1e0\n[    6.513809]  ? set_kthread_struct+0x80/0x80\n[    6.513816]  ret_from_fork+0x22/0x30\n\n[    6.513832] The buggy address belongs to the page:\n[    6.513838] page:00000000bc35e189 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1024d7\n[    6.513847] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)\n[    6.513860] raw: 0\n---truncated---","modified":"2026-03-13T05:18:01.188186Z","published":"2024-03-04T18:15:08.017Z","related":["ALSA-2024:7000","ALSA-2024:7001","SUSE-SU-2024:1320-1","SUSE-SU-2024:1321-1","SUSE-SU-2024:1465-1","SUSE-SU-2024:1466-1","SUSE-SU-2024:1480-1","SUSE-SU-2024:1489-1","SUSE-SU-2024:1490-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/1d72d9f960ccf1052a0630a68c3d358791dbdaaa"},{"type":"FIX","url":"https://git.kernel.org/stable/c/676c572439e58b7ee6b7ca3f1e5595382921045c"},{"type":"FIX","url":"https://git.kernel.org/stable/c/a7f95328c6f0afffdc4555f16e3bbab8bbf0d9be"},{"type":"FIX","url":"https://git.kernel.org/stable/c/dfd5b60b5342b6b505a104e48f08ad9b9bdbbd7b"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-47097.json","unresolved_ranges":[{"events":[{"introduced":"5.4.103"},{"fixed":"5.4.169"}]},{"events":[{"introduced":"5.10.21"},{"fixed":"5.10.89"}]},{"events":[{"introduced":"5.11"},{"fixed":"5.15.12"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc1"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc2"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc3"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc4"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc5"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc6"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}