CVE-2022-49383: Undefined Security Weakness

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

watchdog: rzg2l_wdt: Fix 'BUG: Invalid wait context'

This patch fixes the issue 'BUG: Invalid wait context' during restart() callback by using clk_prepare_enable() instead of pm_runtime_get_sync() for turning on the clocks during restart.

This issue is noticed when testing with renesas_defconfig.

[ 42.213802] reboot: Restarting system [ 42.217860] [ 42.219364] ============================= [ 42.223368] [ BUG: Invalid wait context ] [ 42.227372] 5.17.0-rc5-arm64-renesas-00002-g10393723e35e #522 Not tainted [ 42.234153] ----------------------------- [ 42.238155] systemd-shutdow/1 is trying to lock: [ 42.242766] ffff00000a650828 (&genpd->mlock){+.+.}-{3:3}, at: genpd_lock_mtx+0x14/0x20 [ 42.250709] other info that might help us debug this: [ 42.255753] context-{4:4} [ 42.258368] 2 locks held by systemd-shutdow/1: [ 42.262806] #0: ffff80000944e1c8 (system_transition_mutex#2){+.+.}-{3:3}, at: __do_sys_reboot+0xd0/0x250 [ 42.272388] #1: ffff8000094c4e40 (rcu_read_lock){....}-{1:2}, at: atomic_notifier_call_chain+0x0/0x150 [ 42.281795] stack backtrace: [ 42.284672] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.17.0-rc5-arm64-renesas-00002-g10393723e35e #522 [ 42.294577] Hardware name: Renesas SMARC EVK based on r9a07g044c2 (DT) [ 42.301096] Call trace: [ 42.303538] dump_backtrace+0xcc/0xd8 [ 42.307203] show_stack+0x14/0x30 [ 42.310517] dump_stack_lvl+0x88/0xb0 [ 42.314180] dump_stack+0x14/0x2c [ 42.317492] __lock_acquire+0x1b24/0x1b50 [ 42.321502] lock_acquire+0x120/0x3a8 [ 42.325162] __mutex_lock+0x84/0x8f8 [ 42.328737] mutex_lock_nested+0x30/0x58 [ 42.332658] genpd_lock_mtx+0x14/0x20 [ 42.336319] genpd_runtime_resume+0xc4/0x228 [ 42.340587] __rpm_callback+0x44/0x170 [ 42.344337] rpm_callback+0x64/0x70 [ 42.347824] rpm_resume+0x4e0/0x6b8 [ 42.351310] __pm_runtime_resume+0x50/0x78 [ 42.355404] rzg2l_wdt_restart+0x28/0x68 [ 42.359329] watchdog_restart_notifier+0x1c/0x30 [ 42.363943] atomic_notifier_call_chain+0x94/0x150 [ 42.368732] do_kernel_restart+0x24/0x30 [ 42.372652] machine_restart+0x44/0x70 [ 42.376399] kernel_restart+0x3c/0x60 [ 42.380058] __do_sys_reboot+0x228/0x250 [ 42.383977] __arm64_sys_reboot+0x20/0x28 [ 42.387983] invoke_syscall+0x40/0xf8