Overview

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

clk: meson: align gxbb_32k_clk_sel number of parents with actual count

The following out-of-bounds read has been observed by Christian on a GXBB WeTek Hub:

BUG: KASAN: global-out-of-bounds in __clk_register+0x1b70/0x2418 Read of size 8 at addr ffffd66320cf88e0 by task swapper/0/1

CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.0.0-rc5 #1 PREEMPT Hardware name: WeTek Hub (DT) Call trace: show_stack+0x14/0x20 (C) dump_stack_lvl+0x74/0x94 print_report+0x164/0x4b0 kasan_report+0x98/0xd8 __asan_report_load8_noabort+0x1c/0x24 __clk_register+0x1b70/0x2418 devm_clk_hw_register+0x74/0x15c meson_clkc_init+0xd4/0x20c meson_clkc_syscon_probe+0x5c/0x94 platform_probe+0xbc/0x17c really_probe+0x184/0x844 __driver_probe_device+0x154/0x35c driver_probe_device+0x60/0x188 __driver_attach+0x168/0x4a0 bus_for_each_dev+0xec/0x180 driver_attach+0x38/0x58 bus_add_driver+0x238/0x4c0 driver_register+0x150/0x388 __platform_driver_register+0x54/0x7c gxbb_clkc_driver_init+0x18/0x20 do_one_initcall+0xb8/0x340 kernel_init_freeable+0x49c/0x52c kernel_init+0x24/0x148 ret_from_fork+0x10/0x20

The buggy address belongs to the variable: gxbb_32k_clk_parents+0x60/0x400

The buggy address belongs to a vmalloc virtual mapping The buggy address belongs to the physical page:

Memory state around the buggy address: ffffd66320cf8780: 00 00 00 00 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 ffffd66320cf8800: 00 04 f9 f9 f9 f9 f9 f9 00 04 f9 f9 f9 f9 f9 f9

ffffd66320cf8880: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9 ^ ffffd66320cf8900: 00 01 f9 f9 f9 f9 f9 f9 00 06 f9 f9 f9 f9 f9 f9 ffffd66320cf8980: 00 00 02 f9 f9 f9 f9 f9 00 00 02 f9 f9 f9 f9 f9 ==================================================================

Commit 7915d7d5407c ("clk: amlogic: gxbb: drop non existing 32k clock parent") dropped a non-existing clock parent from the gxbb_32k_clk_sel mux but didn't adjust the hard-coded num_parents field. Fix the actual number of parents of that mux by using ARRAY_SIZE instead (avoiding similar problems in future).

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.