CVE-2025-68335: comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel()
Vulnerability summary
CVE-2025-68335 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.9% of scored vulnerabilities.
No CVSS vector published; no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 46 · Related 45Timeline
- 22-12-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
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] ...
CVSS metrics
Risk metrics not yet published.
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
9%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.19% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: not stated in public data.
Ubuntu156 products
- linuxAll versions (No fix recorded) | < 5.15.0-173.183 | < 6.8.0-110.110 | < 6.17.0-19.19
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1103.110 | < 6.8.0-1052.55 | < 6.17.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linux< 6.1.162-1 | < 6.12.63-1 | < 6.17.12-1
Linux1 product
- linux≥ 00aba6e7b5653a6607238ecdab7172318059d984, < b2a5b172dc05be6c4f2c5542c1bbc6b14d60ff16 | ≥ 00aba6e7b5653a6607238ecdab7172318059d984, < 935ad4b3c325c24fff2c702da403283025ffc722 | ≥ 00aba6e7b5653a6607238ecdab7172318059d984, < 88d99ca5adbd01ff088f5fb2ddeba5755e085e52 | ≥ 00aba6e7b5653a6607238ecdab7172318059d984, < 5caa40e7c6a43e08e3574f990865127705c22861 | ≥ 00aba6e7b5653a6607238ecdab7172318059d984, < d948c53dec36dafe182631457597c49c1f1df5ea | ≥ 00aba6e7b5653a6607238ecdab7172318059d984, < 877adccfacb32687b90714a27cfb09f444fdfa16 | ≥ 00aba6e7b5653a6607238ecdab7172318059d984, < a51f025b5038abd3d22eed2ede4cd46793d89565 | 3.15
3 vendors · 158 products
