CVE-2026-74663

Summary

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

net/sched: reject overly deep qdisc hierarchies

Deep qdisc hierarchies can lead to excessive recursion in qdisc tree walkers and exhaust the kernel stack. The existing loop check does not cover the create-and-graft path, so a hierarchy can still be extended by creating a new child qdisc below an already deep parent.

Store the hierarchy depth in struct Qdisc and update it when qdiscs are grafted. Reject new child qdiscs once the parent is already at the maximum allowed depth.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 9f69bb9fdaa2fe64b68bb62fb84d405784bee540affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8ca8cdb74939581339e1ae370193c0adb5a85336affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 2759acf08a3454866660edcd3ef4e64139f254a6affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a4b14a4df29d36458a943f9b521ddd0f940363ccaffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < e2d658c6427844cee5bc654b436ca68d680b6148affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < dedd34b0f2310e28c5f6d4875cfbf4b7ed821c01affected
LinuxLinux2.6.12affected
LinuxLinux0 < 2.6.12unaffected
LinuxLinux6.1.183 <= 6.1.*unaffected
LinuxLinux6.6.152 <= 6.6.*unaffected
LinuxLinux6.12.104 <= 6.12.*unaffected
LinuxLinux6.18.45 <= 6.18.*unaffected
LinuxLinux7.1.9 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References