{"cve":"CVE-2025-68335","nvd":{"published":"2025-12-22T17:16:01.237","modified":"2026-10-19T21:10:00.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncomedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel()\n\nSyzbot identified an issue [1] in pcl818_ai_cancel(), which stems from\nthe fact that in case of early device detach via pcl818_detach(),\nsubdevice dev->read_subdev may not have initialized its pointer to\n&struct comedi_async as intended. Thus, any such dereferencing of\n&s->async->cmd will lead to general protection fault and kernel crash.\n\nMitigate this problem by removing a call to pcl818_ai_cancel() from\npcl818_detach() altogether. This way, if the subdevice setups its\nsupport for async commands, everything async-related will be\nhandled via subdevice's own ->cancel() function in\ncomedi_device_detach_locked() even before pcl818_detach(). If no\nsupport for asynchronous commands is provided, there is no need\nto cancel anything either.\n\n[1] Syzbot crash:\nOops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI\nKASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]\nCPU: 1 UID: 0 PID: 6050 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025\nRIP: 0010:pcl818_ai_cancel+0x69/0x3f0 drivers/comedi/drivers/pcl818.c:762\n...\nCall Trace:\n <TASK>\n pcl818_detach+0x66/0xd0 drivers/comedi/drivers/pcl818.c:1115\n comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207\n do_devconfig_ioctl drivers/comedi/comedi_fops.c:848 [inline]\n comedi_unlocked_ioctl+0xcde/0x1020 drivers/comedi/comedi_fops.c:2178\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n...","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/5caa40e7c6a43e08e3574f990865127705c22861","https://git.kernel.org/stable/c/877adccfacb32687b90714a27cfb09f444fdfa16","https://git.kernel.org/stable/c/88d99ca5adbd01ff088f5fb2ddeba5755e085e52","https://git.kernel.org/stable/c/935ad4b3c325c24fff2c702da403283025ffc722","https://git.kernel.org/stable/c/a51f025b5038abd3d22eed2ede4cd46793d89565"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-68335","score":0.00193,"percentile":0.08831,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}