comedi: multiq3: sanitize config options in multiq3_attach()
Published Dec 16, 2025
No CVSS score
EPSS 0.20%
Description
Syzbot identified an issue [1] in multiq3_attach() that induces a task timeout due to open() or COMEDI_DEVCONFIG ioctl operations, specifically, in the case of multiq3 driver.
This problem arose when syzkaller managed to craft weird configuration options used to specify the number of channels in encoder subdevice. If a particularly great number is passed to s->n_chan in multiq3_attach() via it->options[2], then multiple calls to multiq3_encoder_reset() at the end of driver-specific attach() method will be running for minutes, thus blocking tasks and affected devices as well.
While this issue is most likely not too dangerous for real-life devices, it still makes sense to sanitize configuration inputs. Enable a sensible limit on the number of encoder chips (4 chips max, each with 2 channels) to stop this behaviour from manifesting.
[1] Syzbot crash: INFO: task syz.2.19:6067 blocked for more than 143 seconds. ... Call Trace: <TASK> context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 __schedule_loop kernel/sched/core.c:6944 [inline] schedule+0x165/0x360 kernel/sched/core.c:6959 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 ...
Affected products
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- Version StatusaffectedConstraints
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- Version
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- Version 2.6.30StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<2.6.30
- Version 5.10.248StatusunaffectedConstraints<=5.10.*
- Version 5.15.198StatusunaffectedConstraints<=5.15.*
- Version 6.1.160StatusunaffectedConstraints<=6.1.*
- Version 6.12.62StatusunaffectedConstraints<=6.12.*
- Version 6.17.12StatusunaffectedConstraints<=6.17.*
- Version 6.18.1StatusunaffectedConstraints<=6.18.*
- Version 6.19StatusunaffectedConstraints<=*
- Version 6.6.120StatusunaffectedConstraints<=6.6.*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
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| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
Red Hat Enterprise Linux 10
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise Linux 9
kernel
Not affected
Red Hat Enterprise Linux 9
kernel-rt
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
No CWE recorded.
References (13)
- https://access.redhat.com/security/cve/CVE-2025-68258 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2422743 Issue Tracking
- https://git.kernel.org/stable/c/049f14557450351750f929ebfff36d849511e132
- https://git.kernel.org/stable/c/4cde9a7e025cc09b88097c70606f6b30c22880f4
- https://git.kernel.org/stable/c/543f4c380c2e1f35e60528df7cb54705cda7fee3
- https://git.kernel.org/stable/c/8952bc1973cd54158c35e06bfb8c29ace7375a48
- https://git.kernel.org/stable/c/8dc2f02d3bada9247f00bfd2e5f61f68c389a0a3
- https://git.kernel.org/stable/c/ad7ed3c9c7b8408e8612697bc43a5441fe386c71
- https://git.kernel.org/stable/c/f24c6e3a39fa355dabfb684c9ca82db579534e72
- https://git.kernel.org/stable/c/f9ff87aac7b37d462246c46d28912d382a8e2ea6
- https://lore.kernel.org/linux-cve-announce/2025121613-CVE-2025-68258-9a76@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2025-68258
- https://www.cve.org/CVERecord?id=CVE-2025-68258
Change history (0)
No recorded changes yet.