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CVE-2026-98554

vlan: ensure sufficient headroom in vlan_dev_hard_header()

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: vlan: ensure sufficient headroom in vlan_dev_hard_header() Callers that only reserve ETH_HLEN or less (such as llc_alloc_frame()), or skbs allocated before dynamic device/headroom changes (e.g. toggling VLAN_FLAG_REORDER_HDR or bonding/team switching slaves), can reach vlan_dev_hard_header() with insufficient headroom and trigger skb_under_panic(). Use skb_cow_head() in vlan_dev_hard_header() when VLAN_FLAG_REORDER_HDR is not set to ensure sufficient headroom for the VLAN header(s) and the underlying device hard header. Use READ_ONCE() to read dev->hard_header_len and dev->needed_headroom as they can be updated concurrently under RTNL (e.g. in vlan_transfer_features()) while vlan_dev_hard_header() runs locklessly on the transmit path. Also avoid LL_RESERVED_SPACE(dev) here so that the extra HH_DATA_MOD alignment padding does not trigger unnecessary pskb_expand_head() reallocations on inner stacked VLAN devices after the outer VLAN header has been pushed.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 55e007fc3b4d76fa4d6b4660f6904fe6ab045a1b; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 5aca8e6a8ff6aeae358c1d9b65447aac416ace95; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 4ba1f57313f36a3ce6f77d593548f0c511f34aa1; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in ca797491f0ae4bfde9039f79f6f1ed7781c9110f; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in cfba0f45553de2b803059e3d539a1e418df24da8; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in c7ee4bea64f559ea8e03260014775b64c720cb5b; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 90d51095371d96747f45bbd8504edf6513e039ef; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in cd5dd68267c4238795fadaf02b3575ca3f8a6500

  • Linux Linux

    2.6.12

  • KernelLinux

    From 2.6.12 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.112; From 6.13.0 · fixed in 6.18.55; From 6.19.0 · fixed in 7.2.9

References 8

git.kernel.org