CVE-2025-68335

CVE-2025-68335 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel() Syzbot identified an issue [1] in pcl818_ai_cancel(), which stems from the fact that in case of early device detach via pcl818_detach(), subdevice dev->read_subdev may not have initialized its pointer to &struct comedi_async as intended. Thus, any such dereferencing of &s->async->cmd will lead to general protection fault and kernel crash. Mitigate this problem by removing a call to pcl818_ai_cancel() from pcl818_detach() altogether. This way, if the subdevice setups its support for async commands, everything async-related will be handled via subdevice's own ->cancel() function in comedi_device_detach_locked() even before pcl818_detach(). If no support for asynchronous commands is provided, there is no need to cancel anything either. [1] Syzbot crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 1 UID: 0 PID: 6050 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pcl818_ai_cancel+0x69/0x3f0 drivers/comedi/drivers/pcl818.c:762 ... Call Trace: <TASK> pcl818_detach+0x66/0xd0 drivers/comedi/drivers/pcl818.c:1115 comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207 do_devconfig_ioctl drivers/comedi/comedi_fops.c:848 [inline] comedi_unlocked_ioctl+0xcde/0x1020 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] ...

Frequently asked questions

What is CVE-2025-68335?
In the Linux kernel, the following vulnerability has been resolved: comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel() Syzbot identified an issue [1] in pcl818_ai_cancel(), which stems from the fact that in case of early device detach via pcl818_detach(), subdevice dev->read_subdev may not have initialized its pointer to &struct comedi_async as intended. Thus, any such dereferencing of &s->async->cmd will lead to general protection fault and kernel crash. Mitigate this problem by removing a call to pcl818_ai_cancel() from pcl818_detach() altogether. This way, if the subdevice setups its support for async commands, everything async-related will be handled via subdevice's own ->cancel() function in comedi_device_detach_locked() even before pcl818_detach(). If no support for asynchronous commands is provided, there is no need to cancel anything either. [1] Syzbot crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 1 UID: 0 PID: 6050 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pcl818_ai_cancel+0x69/0x3f0 drivers/comedi/drivers/pcl818.c:762 ... Call Trace: <TASK> pcl818_detach+0x66/0xd0 drivers/comedi/drivers/pcl818.c:1115 comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207 do_devconfig_ioctl drivers/comedi/comedi_fops.c:848 [inline] comedi_unlocked_ioctl+0xcde/0x1020 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] ...
Is CVE-2025-68335 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-68335?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-68335 have an EU (EUVD) identifier?
Yes. CVE-2025-68335 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204728.
When was CVE-2025-68335 published?
CVE-2025-68335 was published on 2025-12-22 and last updated on 2026-06-17.

References