{"id":"CVE-2025-68335","summary":"comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel()","details":"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-\u003eread_subdev may not have initialized its pointer to\n&struct comedi_async as intended. Thus, any such dereferencing of\n&s-\u003easync-\u003ecmd 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 -\u003ecancel() 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 \u003cTASK\u003e\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...","modified":"2026-04-02T13:03:35.587554Z","published":"2025-12-22T16:14:12.614Z","related":["SUSE-SU-2026:0278-1","SUSE-SU-2026:0281-1","SUSE-SU-2026:0293-1","SUSE-SU-2026:0315-1","SUSE-SU-2026:20207-1","SUSE-SU-2026:20220-1","SUSE-SU-2026:20228-1","SUSE-SU-2026:20477-1","SUSE-SU-2026:20498-1","SUSE-SU-2026:20845-1","SUSE-SU-2026:20876-1","openSUSE-SU-2026:10039-1","openSUSE-SU-2026:10301-1","openSUSE-SU-2026:20145-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68335.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5caa40e7c6a43e08e3574f990865127705c22861"},{"type":"WEB","url":"https://git.kernel.org/stable/c/877adccfacb32687b90714a27cfb09f444fdfa16"},{"type":"WEB","url":"https://git.kernel.org/stable/c/88d99ca5adbd01ff088f5fb2ddeba5755e085e52"},{"type":"WEB","url":"https://git.kernel.org/stable/c/935ad4b3c325c24fff2c702da403283025ffc722"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a51f025b5038abd3d22eed2ede4cd46793d89565"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b2a5b172dc05be6c4f2c5542c1bbc6b14d60ff16"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d948c53dec36dafe182631457597c49c1f1df5ea"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68335.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68335"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"00aba6e7b5653a6607238ecdab7172318059d984"},{"fixed":"b2a5b172dc05be6c4f2c5542c1bbc6b14d60ff16"},{"fixed":"935ad4b3c325c24fff2c702da403283025ffc722"},{"fixed":"88d99ca5adbd01ff088f5fb2ddeba5755e085e52"},{"fixed":"5caa40e7c6a43e08e3574f990865127705c22861"},{"fixed":"d948c53dec36dafe182631457597c49c1f1df5ea"},{"fixed":"877adccfacb32687b90714a27cfb09f444fdfa16"},{"fixed":"a51f025b5038abd3d22eed2ede4cd46793d89565"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-68335.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.15.0"},{"fixed":"5.15.198"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.120"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.62"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.17.12"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.1"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-68335.json"}}],"schema_version":"1.7.5"}