CVE-2025-21821: Linux kernel · fbdev: omap: use threaded IRQ for LCD DMA
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1035.37~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 16:39 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1035.37~22.04.1, 6.8.0-1034.39~22.04.1, 6.8.0-1036.38~22.04.1 +29
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Feb 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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 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.
References
- ubuntu.com/security/CVE-2025-21821 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21821 (opens in a new tab)
- git.kernel.org/linus/e4b6b665df815b4841e71b72f06446884e8aad40 (opens in a new tab)
- git.kernel.org/stable/c/7bbbd311dd503653a2cc86d9226740883051dc92 (opens in a new tab)
- git.kernel.org/stable/c/8392ea100f0b86c234c739c6662f39f0ccc0cefd (opens in a new tab)
- git.kernel.org/stable/c/aa8e22cbedeb626f2a6bda0aea362353d627cd0a (opens in a new tab)
- git.kernel.org/stable/c/e4b6b665df815b4841e71b72f06446884e8aad40 (opens in a new tab)
- git.kernel.org/stable/c/fb6a5edb60921887d7d10619fcdcbee9759552cb (opens in a new tab)
- ubuntu.com/security/notices/USN-7521-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7521-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7521-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7703-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7703-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7703-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7719-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7703-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7737-1 (opens in a new tab)