Out-of-bounds Read in Linux

CVE-2024-50227

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: <TASK> 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.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (13.1th percentile) — read the EPSS interpretation.