{"id":"CVE-2025-68257","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-68257","generatedAt":"2026-10-28T03:38:50.741Z","title":"In the Linux kernel, the following vulnerability has been resolved: comedi: check device's attached status in compat ioctls Syzbot identified an issue [1] that crashes kernel, seemingly due to unexistent callback dev->get_valid_routes().","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncomedi: check device's attached status in compat ioctls\n\nSyzbot identified an issue [1] that crashes kernel, seemingly due to\nunexistent callback dev->get_valid_routes(). By all means, this should\nnot occur as said callback must always be set to\nget_zero_valid_routes() in __comedi_device_postconfig().\n\nAs the crash seems to appear exclusively in i386 kernels, at least,\njudging from [1] reports, the blame lies with compat versions\nof standard IOCTL handlers. Several of them are modified and\ndo not use comedi_unlocked_ioctl(). While functionality of these\nioctls essentially copy their original versions, they do not\nhave required sanity check for device's attached status. This,\nin turn, leads to a possibility of calling select IOCTLs on a\ndevice that has not been properly setup, even via COMEDI_DEVCONFIG.\n\nDoing so on unconfigured devices means that several crucial steps\nare missed, for instance, specifying dev->get_valid_routes()\ncallback.\n\nFix this somewhat crudely by ensuring device's attached status before\nperforming any ioctls, improving logic consistency between modern\nand compat functions.\n\n[1] Syzbot report:\nBUG: kernel NULL pointer dereference, address: 0000000000000000\n...\nCR2: ffffffffffffffd6 CR3: 000000006c717000 CR4: 0000000000352ef0\nCall Trace:\n <TASK>\n get_valid_routes drivers/comedi/comedi_fops.c:1322 [inline]\n parse_insn+0x78c/0x1970 drivers/comedi/comedi_fops.c:1401\n do_insnlist_ioctl+0x272/0x700 drivers/comedi/comedi_fops.c:1594\n compat_insnlist drivers/comedi/comedi_fops.c:3208 [inline]\n comedi_compat_ioctl+0x810/0x990 drivers/comedi/comedi_fops.c:3273\n __do_compat_sys_ioctl fs/ioctl.c:695 [inline]\n __se_compat_sys_ioctl fs/ioctl.c:638 [inline]\n __ia32_compat_sys_ioctl+0x242/0x370 fs/ioctl.c:638\n do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]\n...","published":"2025-12-16T15:15:55.000Z","lastModified":"2026-10-14T13:10:00.000Z","status":"Deferred","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00197,"percentile":0.09349,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0de7d9cd07a2671fa6089173bccc0b2afe6b93ee","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4836ba483a22ebd076c8faaf8293a7295fad4142","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/573b07d2e3d473ee7eb625ef87519922cf01168d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7141915bf0c41cb57d83cdbaf695b8c731b16b71","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aac80e912de306815297a3b74f0426873ffa7dc3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b975f91de5f8f63cf490f0393775cc795f8b0557","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f13895c03620933a58907e3250016f087e39b78c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f6e629dfe6f590091c662a87c9fcf118b1c1c7dc","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-68257","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}