CVE-2026-98531ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST In seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and .len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the maximum payload length and permits shorter payloads (e.g., 0 bytes). When seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via kmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute triggers a 16-byte out-of-bounds read past skb->tail into uninitialized skb->head memory, which is stored in sdata->tun_src and leaked back to userspace via SEG6_CMD_GET_TUNSRC. Switch SEG6_ATTR_DST in seg6_genl_policy to NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink validation rejects any attribute whose length is not exactly sizeof(struct in6_addr) with -ERANGE. Tested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC Generic Netlink message with a 0-byte SEG6_ATTR_DST attribute followed by SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC succeeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of uninitialized kernel heap memory (tun_src = 836a61ecc4d25a1042a8d60411cfb378); with this patch applied, SEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with -ERANGE (-34) and tun_src remains zeroed.
- CVSS
- Not yet scored
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 18, 2026
- First seen by InfoSec Signals
- Oct 18, 2026
Affected products
Linux Linux linux:linux (from the name) | 915d7e5e5930b4f01d0971d93b9b25ed17d221aa builds before 050a0aa3c80907b8c60a396b7e04d48d8b1a9e70; 915d7e5e5930b4f01d0971d93b9b25ed17d221aa builds before 209eefebee54c4a5f01d68b61e8ac9881eca2de9; from 915d7e5e5930b4f01d0971d93b9b25ed17d221aa before e3ac68c1cdc2535d127b2bfd50c263d16c8e4199; 915d7e5e5930b4f01d0971d93b9b25ed17d221aa builds before 66bf65fa109326e4c4ddeb0b94093379f72838fd; from 915d7e5e5930b4f01d0971d93b9b25ed17d221aa before 195813bb7324c338eaba0aaa02b18681ee65b670; 915d7e5e5930b4f01d0971d93b9b25ed17d221aa builds before 6fcfc362344edea745a69f3a705de50b731f3418; from 915d7e5e5930b4f01d0971d93b9b25ed17d221aa before 94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e; 915d7e5e5930b4f01d0971d93b9b25ed17d221aa builds before 2d959c75c27f90e9ec489d18ce5ee6b852ad4741 | CNA record |
References
- https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70
- https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9
- https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199
- https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd
- https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670
- https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418
- https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e
- https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.