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CVE-2026-43186

ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16, and 1 more
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: total

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data() On the receive path, __ioam6_fill_trace_data() uses trace->nodelen to decide how much data to write for each node. It trusts this field as-is from the incoming packet, with no consistency check against trace->type (the 24-bit field that tells which data items are present). A crafted packet can set nodelen=0 while setting type bits 0-21, causing the function to write ~100 bytes past the allocated region (into skb_shared_info), which corrupts adjacent heap memory and leads to a kernel panic. Add a shared helper ioam6_trace_compute_nodelen() in ioam6.c to derive the expected nodelen from the type field, and use it: • in ioam6_iptunnel.c (send path, existing validation) to replace the open-coded computation; • in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose nodelen is inconsistent with the type field, before any data is written. Per RFC 9197, bits 12-21 are each short (4-octet) fields, so they are included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to 0xff1ffc00).

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • Linux Linux

    From 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 · fixed in f4d9d4b8fd839719d564651671e24c62c545c23b; From 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 · fixed in fb3c662fafebc5b9d74417ed1de8759f6bb72143; From 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 · fixed in 632d233cf2e64a46865ae2c064ae3c9df7c8864f; From 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 · fixed in 0591d6509c2ff13f09ea2998434aba0c0472e978; From 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 · fixed in e90346a2f1e8917d5760a44a1f61c44e3b36d96b; From 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 · fixed in ea3632aefc04205436868541638e26f4a74d5637; From 9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 · fixed in 6db8b56eed62baacaf37486e83378a72635c04cc

  • Linux Linux

    5.15

  • KernelLinux

    From 5.15.0 · fixed in 5.15.202; From 5.16.0 · fixed in 6.1.165; From 6.2.0 · fixed in 6.6.128; From 6.7.0 · fixed in 6.12.75; From 6.13.0 · fixed in 6.18.16; From 6.19.0 · fixed in 6.19.6

References 7

git.kernel.org