CVE-2025-21821

/// Technical description

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

fbdev: omap: use threaded IRQ for LCD DMA

When using touchscreen and framebuffer, Nokia 770 crashes easily with:

BUG: scheduling while atomic: irq/144-ads7846/82/0x00010000

Modules linked in: usb_f_ecm g_ether usb_f_rndis u_ether libcomposite configfs omap_udc ohci_omap ohci_hcd

CPU: 0 UID: 0 PID: 82 Comm: irq/144-ads7846 Not tainted 6.12.7-770 #2

Hardware name: Nokia 770

Call trace:

unwind_backtrace from show_stack+0x10/0x14

show_stack from dump_stack_lvl+0x54/0x5c

dump_stack_lvl from __schedule_bug+0x50/0x70

__schedule_bug from __schedule+0x4d4/0x5bc

__schedule from schedule+0x34/0xa0

schedule from schedule_preempt_disabled+0xc/0x10

schedule_preempt_disabled from __mutex_lock.constprop.0+0x218/0x3b4

__mutex_lock.constprop.0 from clk_prepare_lock+0x38/0xe4

clk_prepare_lock from clk_set_rate+0x18/0x154

clk_set_rate from sossi_read_data+0x4c/0x168

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References