CVE-2021-47097

HIGH
Published Mar 4, 2024 Modified Feb 14, 2025 CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: Input: elantech - fix stack out of bound access in elantech_change_report_id() The array param[] in elantech_change_report_id() must be at least 3 bytes, because elantech_read_reg_params() is calling ps2_command() with PSMOUSE_CMD_GETINFO, that is going to access 3 bytes from param[], but it's defined in the stack as an array of 2 bytes, therefore we have a potential stack out-of-bounds access here, also confirmed by KASAN: [ 6.512374] BUG: KASAN: stack-out-of-bounds in __ps2_command+0x372/0x7e0 [ 6.512397] Read of size 1 at addr ffff8881024d77c2 by task kworker/2:1/118 [ 6.512416] CPU: 2 PID: 118 Comm: kworker/2:1 Not tainted 5.13.0-22-generic #22+arighi20211110 [ 6.512428] Hardware name: LENOVO 20T8000QGE/20T8000QGE, BIOS R1AET32W (1.08 ) 08/14/2020 [ 6.512436] Workqueue: events_long serio_handle_event [ 6.512453] Call Trace: [ 6.512462] show_stack+0x52/0x58 [ 6.512474] dump_stack+0xa1/0xd3 [ 6.512487] print_address_description.constprop.0+0x1d/0x140 [ 6.512502] ? __ps2_command+0x372/0x7e0 [ 6.512516] __kasan_report.cold+0x7d/0x112 [ 6.512527] ? _raw_write_lock_irq+0x20/0xd0 [ 6.512539] ? __ps2_command+0x372/0x7e0 [ 6.512552] kasan_report+0x3c/0x50 [ 6.512564] __asan_load1+0x6a/0x70 [ 6.512575] __ps2_command+0x372/0x7e0 [ 6.512589] ? ps2_drain+0x240/0x240 [ 6.512601] ? dev_printk_emit+0xa2/0xd3 [ 6.512612] ? dev_vprintk_emit+0xc5/0xc5 [ 6.512621] ? __kasan_check_write+0x14/0x20 [ 6.512634] ? mutex_lock+0x8f/0xe0 [ 6.512643] ? __mutex_lock_slowpath+0x20/0x20 [ 6.512655] ps2_command+0x52/0x90 [ 6.512670] elantech_ps2_command+0x4f/0xc0 [psmouse] [ 6.512734] elantech_change_report_id+0x1e6/0x256 [psmouse] [ 6.512799] ? elantech_report_trackpoint.constprop.0.cold+0xd/0xd [psmouse] [ 6.512863] ? ps2_command+0x7f/0x90 [ 6.512877] elantech_query_info.cold+0x6bd/0x9ed [psmouse] [ 6.512943] ? elantech_setup_ps2+0x460/0x460 [psmouse] [ 6.513005] ? psmouse_reset+0x69/0xb0 [psmouse] [ 6.513064] ? psmouse_attr_set_helper+0x2a0/0x2a0 [psmouse] [ 6.513122] ? phys_pmd_init+0x30e/0x521 [ 6.513137] elantech_init+0x8a/0x200 [psmouse] [ 6.513200] ? elantech_init_ps2+0xf0/0xf0 [psmouse] [ 6.513249] ? elantech_query_info+0x440/0x440 [psmouse] [ 6.513296] ? synaptics_send_cmd+0x60/0x60 [psmouse] [ 6.513342] ? elantech_query_info+0x440/0x440 [psmouse] [ 6.513388] ? psmouse_try_protocol+0x11e/0x170 [psmouse] [ 6.513432] psmouse_extensions+0x65d/0x6e0 [psmouse] [ 6.513476] ? psmouse_try_protocol+0x170/0x170 [psmouse] [ 6.513519] ? mutex_unlock+0x22/0x40 [ 6.513526] ? ps2_command+0x7f/0x90 [ 6.513536] ? psmouse_probe+0xa3/0xf0 [psmouse] [ 6.513580] psmouse_switch_protocol+0x27d/0x2e0 [psmouse] [ 6.513624] psmouse_connect+0x272/0x530 [psmouse] [ 6.513669] serio_driver_probe+0x55/0x70 [ 6.513679] really_probe+0x190/0x720 [ 6.513689] driver_probe_device+0x160/0x1f0 [ 6.513697] device_driver_attach+0x119/0x130 [ 6.513705] ? device_driver_attach+0x130/0x130 [ 6.513713] __driver_attach+0xe7/0x1a0 [ 6.513720] ? device_driver_attach+0x130/0x130 [ 6.513728] bus_for_each_dev+0xfb/0x150 [ 6.513738] ? subsys_dev_iter_exit+0x10/0x10 [ 6.513748] ? _raw_write_unlock_bh+0x30/0x30 [ 6.513757] driver_attach+0x2d/0x40 [ 6.513764] serio_handle_event+0x199/0x3d0 [ 6.513775] process_one_work+0x471/0x740 [ 6.513785] worker_thread+0x2d2/0x790 [ 6.513794] ? process_one_work+0x740/0x740 [ 6.513802] kthread+0x1b4/0x1e0 [ 6.513809] ? set_kthread_struct+0x80/0x80 [ 6.513816] ret_from_fork+0x22/0x30 [ 6.513832] The buggy address belongs to the page: [ 6.513838] page:00000000bc35e189 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1024d7 [ 6.513847] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) [ 6.513860] raw: 0 ---truncated---

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CVSS v3.1 Score

7.1
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Frequently Asked Questions

What is CVE-2021-47097? +
In the Linux kernel, the following vulnerability has been resolved: Input: elantech - fix stack out of bound access in elantech_change_report_id() The array param[] in elantech_change_report_id() must be at least 3 bytes, because elantech_read_reg_params() is calling ps2_command() with PSMOUSE_CMD_GETINFO, that is going to access 3 bytes from param[], but it's defined in the stack as an array of 2 bytes, therefore we have a potential stack out-of-bounds access here, also confirmed by KASAN: [ 6.512374] BUG: KASAN: stack-out-of-bounds in __ps2_command+0x372/0x7e0 [ 6.512397] Read of size 1 at addr ffff8881024d77c2 by task kworker/2:1/118 [ 6.512416] CPU: 2 PID: 118 Comm: kworker/2:1 Not tainted 5.13.0-22-generic #22+arighi20211110 [ 6.512428] Hardware name: LENOVO 20T8000QGE/20T8000QGE, BIOS R1AET32W (1.08 ) 08/14/2020 [ 6.512436] Workqueue: events_long serio_handle_event [ 6.512453] Call Trace: [ 6.512462] show_stack+0x52/0x58 [ 6.512474] dump_stack+0xa1/0xd3 [ 6.512487] print_address_description.constprop.0+0x1d/0x140 [ 6.512502] ? __ps2_command+0x372/0x7e0 [ 6.512516] __kasan_report.cold+0x7d/0x112 [ 6.512527] ? _raw_write_lock_irq+0x20/0xd0 [ 6.512539] ? __ps2_command+0x372/0x7e0 [ 6.512552] kasan_report+0x3c/0x50 [ 6.512564] __asan_load1+0x6a/0x70 [ 6.512575] __ps2_command+0x372/0x7e0 [ 6.512589] ? ps2_drain+0x240/0x240 [ 6.512601] ? dev_printk_emit+0xa2/0xd3 [ 6.512612] ? dev_vprintk_emit+0xc5/0xc5 [ 6.512621] ? __kasan_check_write+0x14/0x20 [ 6.512634] ? mutex_lock+0x8f/0xe0 [ 6.512643] ? __mutex_lock_slowpath+0x20/0x20 [ 6.512655] ps2_command+0x52/0x90 [ 6.512670] elantech_ps2_command+0x4f/0xc0 [psmouse] [ 6.512734] elantech_change_report_id+0x1e6/0x256 [psmouse] [ 6.512799] ? elantech_report_trackpoint.constprop.0.cold+0xd/0xd [psmouse] [ 6.512863] ? ps2_command+0x7f/0x90 [ 6.512877] elantech_query_info.cold+0x6bd/0x9ed [psmouse] [ 6.512943] ? elantech_setup_ps2+0x460/0x460 [psmouse] [ 6.513005] ? psmouse_reset+0x69/0xb0 [psmouse] [ 6.513064] ? psmouse_attr_set_helper+0x2a0/0x2a0 [psmouse] [ 6.513122] ? phys_pmd_init+0x30e/0x521 [ 6.513137] elantech_init+0x8a/0x200 [psmouse] [ 6.513200] ? elantech_init_ps2+0xf0/0xf0 [psmouse] [ 6.513249] ? elantech_query_info+0x440/0x440 [psmouse] [ 6.513296] ? synaptics_send_cmd+0x60/0x60 [psmouse] [ 6.513342] ? elantech_query_info+0x440/0x440 [psmouse] [ 6.513388] ? psmouse_try_protocol+0x11e/0x170 [psmouse] [ 6.513432] psmouse_extensions+0x65d/0x6e0 [psmouse] [ 6.513476] ? psmouse_try_protocol+0x170/0x170 [psmouse] [ 6.513519] ? mutex_unlock+0x22/0x40 [ 6.513526] ? ps2_command+0x7f/0x90 [ 6.513536] ? psmouse_probe+0xa3/0xf0 [psmouse] [ 6.513580] psmouse_switch_protocol+0x27d/0x2e0 [psmouse] [ 6.513624] psmouse_connect+0x272/0x530 [psmouse] [ 6.513669] serio_driver_probe+0x55/0x70 [ 6.513679] really_probe+0x190/0x720 [ 6.513689] driver_probe_device+0x160/0x1f0 [ 6.513697] device_driver_attach+0x119/0x130 [ 6.513705] ? device_driver_attach+0x130/0x130 [ 6.513713] __driver_attach+0xe7/0x1a0 [ 6.513720] ? device_driver_attach+0x130/0x130 [ 6.513728] bus_for_each_dev+0xfb/0x150 [ 6.513738] ? subsys_dev_iter_exit+0x10/0x10 [ 6.513748] ? _raw_write_unlock_bh+0x30/0x30 [ 6.513757] driver_attach+0x2d/0x40 [ 6.513764] serio_handle_event+0x199/0x3d0 [ 6.513775] process_one_work+0x471/0x740 [ 6.513785] worker_thread+0x2d2/0x790 [ 6.513794] ? process_one_work+0x740/0x740 [ 6.513802] kthread+0x1b4/0x1e0 [ 6.513809] ? set_kthread_struct+0x80/0x80 [ 6.513816] ret_from_fork+0x22/0x30 [ 6.513832] The buggy address belongs to the page: [ 6.513838] page:00000000bc35e189 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1024d7 [ 6.513847] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) [ 6.513860] raw: 0 ---truncated--- It has a CVSS v3.1 base score of 7.1 (HIGH).
How severe is CVE-2021-47097? +
CVE-2021-47097 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2021-47097? +
CVE-2021-47097 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47097? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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