GHSA-29X7-MV82-CJ8R
Vulnerability from github – Published: 2026-08-15 15:30 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()
rds_tcp_laddr_check() looks up a scoped IPv6 interface with dev_get_by_index_rcu(), drops the RCU read-side lock, and only then passes the bare struct net_device * into ipv6_chk_addr().
dev_get_by_index_rcu() only keeps the device alive within the same RCU read-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can free the net_device; ipv6_chk_addr() then dereferences the stale pointer in __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading freed memory.
Keep the RCU read-side lock held across the ipv6_chk_addr() call instead of dropping it right after the lookup, so the device cannot be freed while it is in use.
BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998) Read of size 8 at addr ffff8880106ec000 by task exploit/153 Call Trace: ... kasan_report (mm/kasan/report.c:595) __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998) ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972) rds_tcp_laddr_check (net/rds/tcp.c:370) rds_bind (net/rds/bind.c:248) __sys_bind (net/socket.c:1920) __x64_sys_bind (net/socket.c:1956) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
{
"affected": [],
"aliases": [
"CVE-2026-74563"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T13:18:01Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()\n\nrds_tcp_laddr_check() looks up a scoped IPv6 interface with\ndev_get_by_index_rcu(), drops the RCU read-side lock, and only then\npasses the bare struct net_device * into ipv6_chk_addr().\n\ndev_get_by_index_rcu() only keeps the device alive within the same RCU\nread-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can\nfree the net_device; ipv6_chk_addr() then dereferences the stale pointer\nin __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading\nfreed memory.\n\nKeep the RCU read-side lock held across the ipv6_chk_addr() call instead\nof dropping it right after the lookup, so the device cannot be freed\nwhile it is in use.\n\n BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)\n Read of size 8 at addr ffff8880106ec000 by task exploit/153\n Call Trace:\n ...\n kasan_report (mm/kasan/report.c:595)\n __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)\n ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972)\n rds_tcp_laddr_check (net/rds/tcp.c:370)\n rds_bind (net/rds/bind.c:248)\n __sys_bind (net/socket.c:1920)\n __x64_sys_bind (net/socket.c:1956)\n do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)",
"id": "GHSA-29x7-mv82-cj8r",
"modified": "2026-08-17T06:33:53Z",
"published": "2026-08-15T15:30:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74563"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/78f75d632f74b8de0f081a128588f7c37d0d1164"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8398bc477d3cb3e2b018a5aaac2bec0f69acda30"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b1d480fce05f857dc438080cd8c9244b84a83494"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.