Medium · published December 27, 2024
In the Linux kernel, the following vulnerability has been resolved:
pmdomain: imx: gpcv2: Adjust delay after power up handshake
The udelay(5) is not enough, sometimes below kernel panic
still be triggered:
[ 4.012973] Kernel panic - not syncing: Asynchronous SError Interrupt
[ 4.012976] CPU: 2 UID: 0 PID: 186 Comm: (udev-worker) Not tainted 6.12.0-rc2-0.0.0-devel-00004-g8b1b79e88956 #1
[ 4.012982] Hardware name: Toradex Verdin iMX8M Plus WB on Dahlia Board (DT)
[ 4.012985] Call trace:
[...]
[ 4.013029] arm64_serror_panic+0x64/0x70
[ 4.013034] do_serror+0x3c/0x70
[ 4.013039] el1h_64_error_handler+0x30/0x54
[ 4.013046] el1h_64_error+0x64/0x68
[ 4.013050] clk_imx8mp_audiomix_runtime_resume+0x38/0x48
[ 4.013059] __genpd_runtime_resume+0x30/0x80
[ 4.013066] genpd_runtime_resume+0x114/0x29c
[ 4.013073] __rpm_callback+0x48/0x1e0
[ 4.013079] rpm_callback+0x68/0x80
[ 4.013084] rpm_resume+0x3bc/0x6a0
[ 4.013089] __pm_runtime_resume+0x50/0x9c
[ 4.013095] pm_runtime_get_suppliers+0x60/0x8c
[ 4.013101] __driver_probe_device+0x4c/0x14c
[ 4.013108] driver_probe_device+0x3c/0x120
[ 4.013114] __driver_attach+0xc4/0x200
[ 4.013119] bus_for_each_dev+0x7c/0xe0
[ 4.013125] driver_attach+0x24/0x30
[ 4.013130] bus_add_driver+0x110/0x240
[ 4.013135] driver_register+0x68/0x124
[ 4.013142] __platform_driver_register+0x24/0x30
[ 4.013149] sdma_driver_init+0x20/0x1000 [imx_sdma]
[ 4.013163] do_one_initcall+0x60/0x1e0
[ 4.013168] do_init_module+0x5c/0x21c
[ 4.013175] load_module+0x1a98/0x205c
[ 4.013181] init_module_from_file+0x88/0xd4
[ 4.013187] __arm64_sys_finit_module+0x258/0x350
[ 4.013194] invoke_syscall.constprop.0+0x50/0xe0
[ 4.013202] do_el0_svc+0xa8/0xe0
[ 4.013208] el0_svc+0x3c/0x140
[ 4.013215] el0t_64_sync_handler+0x120/0x12c
[ 4.013222] el0t_64_sync+0x190/0x194
[ 4.013228] SMP: stopping secondary CPUs
The correct way is to wait handshake, but it needs BUS clock of
BLK-CTL be enabled, which is in separate driver. So delay is the
only option here. The udelay(10) is a data got by experiment.