CVE-2026-74563 (GCVE-0-2026-74563)
Vulnerability from cvelistv5
Published
2026-08-15 12:28
Modified
2026-08-19 16:39
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In 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)
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 Version: eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/rds/tcp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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{
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]
},
{
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.19"
},
{
"lessThan": "4.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.151",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.265",
"versionStartIncluding": "4.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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{
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{
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},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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)"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The slab use-after-free is reached via the bind(2) syscall on an AF_RDS socket with a link-local IPv6 address and non-zero scope_id; the KASAN reproducer follows bind()-\u003erds_bind()-\u003erds_tcp_laddr_check(), requiring on-host access to race bind against RTM_DELLINK netlink deletion of the referenced netdev.\nAC:L - Exploitation requires racing rds_tcp_laddr_check() against RTM_DELLINK freeing the netdev; the attacker controls both sides by concurrently calling bind() and deleting the interface via netlink (e.g., a veth in a user namespace) and can retry until the race succeeds.\nPR:L - An unprivileged local user can create AF_RDS sockets and call bind(); the RTM_DELLINK race is achievable with CAP_NET_ADMIN obtainable inside an unprivileged user+network namespace (unshare -Urn), not requiring init-namespace root.\nUI:N - No victim interaction is required; exploitation is fully attacker-driven through bind/netlink syscalls without needing another user to mount a filesystem, click, or open a file.\nS:U - Impact is confined to kernel memory corruption and potential privilege escalation within the same kernel/host security boundary; this is not a VM-guest-to-host escape, sandbox escape, or cross-authority boundary crossing.\nC:H - The bug is a slab use-after-free read of a freed struct net_device in __ipv6_chk_addr_and_flags() via a stale pointer passed to ipv6_chk_addr(); UAF reads of kernel heap objects can disclose sensitive memory and enable further exploitation.\nI:H - Use-after-free on struct net_device heap memory provides memory corruption primitives that can be groomed for arbitrary kernel writes, control-flow hijacking, and local privilege escalation, not merely a bounded or transient error.\nA:H - The reported KASAN slab-use-after-free causes kernel oops/panic during the stale dereference in the IPv6 address-check path; UAF conditions are inherently crash-prone even when not fully weaponized for code execution."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-19T16:39:02.416Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/f8a8977af2134a1d91e5f9773cb7d9d53278c830"
},
{
"url": "https://git.kernel.org/stable/c/ba95bce5dfe6e2ef602a87e0557225f2934ccb5c"
},
{
"url": "https://git.kernel.org/stable/c/c4933624a6f416ecfcc31ab58d585da1207a0597"
},
{
"url": "https://git.kernel.org/stable/c/76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef"
},
{
"url": "https://git.kernel.org/stable/c/f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff"
},
{
"url": "https://git.kernel.org/stable/c/b1d480fce05f857dc438080cd8c9244b84a83494"
},
{
"url": "https://git.kernel.org/stable/c/8398bc477d3cb3e2b018a5aaac2bec0f69acda30"
},
{
"url": "https://git.kernel.org/stable/c/78f75d632f74b8de0f081a128588f7c37d0d1164"
}
],
"title": "rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74563",
"datePublished": "2026-08-15T12:28:05.768Z",
"dateReserved": "2026-08-15T05:44:03.916Z",
"dateUpdated": "2026-08-19T16:39:02.416Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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