CVE-2026-43427

Summary

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

usb: class: cdc-wdm: fix reordering issue in read code path

Quoting the bug report:

Due to compiler optimization or CPU out-of-order execution, the desc->length update can be reordered before the memmove. If this happens, wdm_read() can see the new length and call copy_to_user() on uninitialized memory. This also violates LKMM data race rules [1].

Fix it by using WRITE_ONCE and memory barriers.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < 638328ca9c17ae6511ad62198c57bae32ffa3c91affected
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < 170e8daca24da6edb4be82ab01abf44e87af387baffected
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < c8fa96ed021923dae147bcd9f9205b8df7b82360affected
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < 4ee3062bf2c9a722afef429826e8607eaf3fc6a0affected
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < 276aef0fd2b92f41b920ac891c72cadeee957934affected
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < 67ed312124bb1b61858778ac0b985b48961c862aaffected
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < e3c874b05901dc519054b5107d16620e6d2b5feaaffected
LinuxLinuxafba937e540c902c989cd516fd97ea0c8499bb27 < 8df672bfe3ec2268c2636584202755898e547173affected
LinuxLinux2.6.26affected
LinuxLinux0 < 2.6.26unaffected
LinuxLinux5.10.253 <= 5.10.*unaffected
LinuxLinux5.15.203 <= 5.15.*unaffected
LinuxLinux6.1.167 <= 6.1.*unaffected
LinuxLinux6.6.130 <= 6.6.*unaffected
LinuxLinux6.12.78 <= 6.12.*unaffected
LinuxLinux6.18.19 <= 6.18.*unaffected
LinuxLinux6.19.9 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References