CVE-2026-68178

Summary

In the Linux kernel, the following vulnerability has been resolved:

misc: nsm: pin the module while the device is open

misc_open() installs a misc driver's file operations with fops_get(), which pins file_operations::owner before replacing the file's f_op. The NSM misc device leaves nsm_dev_fops.owner unset, so opening /dev/nsm does not take a module reference on the nsm driver.

If the driver is built as a module, an open file descriptor can therefore survive rmmod of the module that provides its ioctl callbacks. A later ioctl through that descriptor can call into unloaded module text.

Set nsm_dev_fops.owner to THIS_MODULE so the misc core holds the module while any /dev/nsm file descriptor is open, matching the lifetime expectation for the installed file operations.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 1996639f824ce9468395cdb7bcb8f467fa787e77affected
LinuxLinuxb9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 1da310b94504d42001e9c32c43c5dc105b777e5faffected
LinuxLinuxb9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 9e9a82d00c3d10129fc310a7547b24a679d5d920affected
LinuxLinuxb9873755a6c8ccfce79094c4dce9efa3ecb1a749 < 3b231f1e9990f4c21220d0a69733ce2105891ff9affected
LinuxLinux6.8affected
LinuxLinux0 < 6.8unaffected
LinuxLinux6.12.101 <= 6.12.*unaffected
LinuxLinux6.18.42 <= 6.18.*unaffected
LinuxLinux7.1.6 <= 7.1.*unaffected
LinuxLinux7.2-rc5 <= *unaffected

Weaknesses

References