CVE-2025-21821 | fbdev: omap: use threaded IRQ for LCD DMA

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 sossi_read_data from hwa742_read_reg+0x5c/0x8c hwa742_read_reg from send_frame_handler+0xfc/0x300 send_frame_handler from process_pending_requests+0x74/0xd0 process_pending_requests from lcd_dma_irq_handler+0x50/0x74 lcd_dma_irq_handler from __handle_irq_event_percpu+0x44/0x130 __handle_irq_event_percpu from handle_irq_event+0x28/0x68 handle_irq_event from handle_level_irq+0x9c/0x170 handle_level_irq from generic_handle_domain_irq+0x2c/0x3c generic_handle_domain_irq from omap1_handle_irq+0x40/0x8c omap1_handle_irq from generic_handle_arch_irq+0x28/0x3c generic_handle_arch_irq from call_with_stack+0x1c/0x24 call_with_stack from __irq_svc+0x94/0xa8 Exception stack(0xc5255da0 to 0xc5255de8) 5da0: 00000001 c22fc620 00000000 00000000 c08384a8 c106fc00 00000000 c240c248 5dc0: c113a600 c3f6ec30 00000001 00000000 c22fc620 c5255df0 c22fc620 c0279a94 5de0: 60000013 ffffffff __irq_svc from clk_prepare_lock+0x4c/0xe4 clk_prepare_lock from clk_get_rate+0x10/0x74 clk_get_rate from uwire_setup_transfer+0x40/0x180 uwire_setup_transfer from spi_bitbang_transfer_one+0x2c/0x9c spi_bitbang_transfer_one from spi_transfer_one_message+0x2d0/0x664 spi_transfer_one_message from __spi_pump_transfer_message+0x29c/0x498 __spi_pump_transfer_message from __spi_sync+0x1f8/0x2e8 __spi_sync from spi_sync+0x24/0x40 spi_sync from ads7846_halfd_read_state+0x5c/0x1c0 ads7846_halfd_read_state from ads7846_irq+0x58/0x348 ads7846_irq from irq_thread_fn+0x1c/0x78 irq_thread_fn from irq_thread+0x120/0x228 irq_thread from kthread+0xc8/0xe8 kthread from ret_from_fork+0x14/0x28 As a quick fix, switch to a threaded IRQ which provides a stable system.

Published: 2025-02-27 Last update: 2025-11-03 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-21821 is rated Low Risk (24.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-21821

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-04 0.05% 0.03% -0.02%
2 2025-10-31 0.03% 0.05% +0.02%
3 2025-10-28 — 0.03% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21821

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-21821

OS Trackers for CVE-2025-21821

vendor priority summary link
debian unimportant CVE-2025-21821 unimportant priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-21821
redhat low — https://access.redhat.com/security/cve/CVE-2025-21821
suse medium — https://www.suse.com/security/cve/CVE-2025-21821/
ubuntu medium CVE-2025-21821 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 154, released 135, needed 75, not-affected 42. https://ubuntu.com/security/CVE-2025-21821

Affected software / configurations for CVE-2025-21821

Vendor Product Version Raw CPE
linux linux_kernel < 6.1.129 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.79 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.16 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.13.4 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2025-21821

cvelogic Threat Intelligence