Description

In the Linux kernel, the following vulnerability has been resolved:

thunderbolt: Fix KASAN reported stack out-of-bounds read in tb_retimer_scan()

KASAN reported following issue:

BUG: KASAN: stack-out-of-bounds in tb_retimer_scan+0xffe/0x1550 [thunderbolt]
Read of size 4 at addr ffff88810111fc1c by task kworker/u56:0/11
CPU: 0 UID: 0 PID: 11 Comm: kworker/u56:0 Tainted: G U 6.11.0+ #1387
Tainted: [U]=USER
Workqueue: thunderbolt0 tb_handle_hotplug [thunderbolt]
Call Trace:

dump_stack_lvl+0x6c/0x90
print_report+0xd1/0x630
kasan_report+0xdb/0x110
__asan_report_load4_noabort+0x14/0x20
tb_retimer_scan+0xffe/0x1550 [thunderbolt]
tb_scan_port+0xa6f/0x2060 [thunderbolt]
tb_handle_hotplug+0x17b1/0x3080 [thunderbolt]
process_one_work+0x626/0x1100
worker_thread+0x6c8/0xfa0
kthread+0x2c8/0x3a0
ret_from_fork+0x3a/0x80
ret_from_fork_asm+0x1a/0x30

This happens because the loop variable still gets incremented by one so
max becomes 3 instead of 2, and this makes the second loop read past the
the array declared on the stack.

Fix this by assigning to max directly in the loop body.

Classification

CVE ID: CVE-2024-50227

CVSS Base Severity: HIGH

CVSS Base Score: 7.1

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

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 5.61% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2024-50227
https://git.kernel.org/stable/c/08b2771e9270fbe1ed4fbbe93abe05ac7fe9861d
https://git.kernel.org/stable/c/e9e1b20fae7de06ba36dd3f8dba858157bad233d

Timeline