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CVE-2026-98432

ipv4: free inet_opt and ireq_opt after an RCU grace period

Products / packages Linux

Published

Share

Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 14/11/2026, 22:55:31 UTC
Linux · CVSS:3.1 · 9.8
Assessment vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity

critical9.8

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Fix status not established

No structured fix or guidance is available here. Check the latest publisher advisory.

What this means

In the Linux kernel, the following vulnerability has been resolved:

Source excerpt · Linux

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Linux · Linux

Linux

8 ranges
Linux version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

079096f103faca2dd87342cca6f23d4b34da8871 → before b3b027ef0cd322bfa839b9aaf5b27551eea54cf6

git versions

079096f103faca2dd87342cca6f23d4b34da8871 → before 95a8c8fa9f27dce64c40c41c062de7728bf34ab5

git versions

079096f103faca2dd87342cca6f23d4b34da8871 → before 89b5b1eb7d633c33832b7ff2c02e19a144705036

git versions

079096f103faca2dd87342cca6f23d4b34da8871 → before 742f73df544e03744f2981c467d6542fe8172a2a

git versions

079096f103faca2dd87342cca6f23d4b34da8871 → before 11a03ce3c4a62d84c10ccdfe47f8075006498568

git versions

079096f103faca2dd87342cca6f23d4b34da8871 → before a47406c769f72c070386985488f1c4d057df86b2

git versions

079096f103faca2dd87342cca6f23d4b34da8871 → before 26d4c36d318cffbbd160884a0e4cec0da4da4936

git versions

079096f103faca2dd87342cca6f23d4b34da8871 → before e3f33b0a1d89d738e2b913dab519226eaf76e15b

git versions

unaffected

unknown

Other versions: unaffected

Linux · Linux

Linux

10 ranges
Linux version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

4.4

unaffected

0 → before 4.4

semver versions

5.10.272 → through 5.10.*

semver versions

5.15.223 → through 5.15.*

semver versions

6.1.190 → through 6.1.*

semver versions

6.6.159 → through 6.6.*

semver versions

6.12.113 → through 6.12.*

semver versions

6.18.56 → through 6.18.*

semver versions

7.2.10 → through 7.2.*

semver versions

7.3 → through *

original_commit_for_fix versions

unknown

Other versions: affected

Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher description

In the Linux kernel, the following vulnerability has been resolved:

ipv4: free inet_opt and ireq_opt after an RCU grace period

tcp_v4_syn_recv_sock() transfers ownership of ireq->ireq_opt to the child socket (newinet->inet_opt) without copying it.

Another cpu can concurrently process a retransmitted SYN for the same request socket, and send a SYNACK from tcp_check_req(). tcp_v4_send_synack() and inet_csk_route_req() read ireq->ireq_opt under rcu_read_lock() only, and ip_build_and_send_pkt() and ip_options_build() then read opt->optlen twice.

Note that the SYNACK timer itself is not an issue: it holds a reference on its request socket, and inet_csk_reqsk_queue_drop() calls timer_delete_sync() before the child can be freed.

Since commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table"), request sockets are processed without holding the listener lock, so nothing prevents the child socket from being freed while the SYNACK is still being built. TCP child sockets do not have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt with a plain kfree(), leading to a use-after-free in ip_options_build().

A similar issue exists with request socket migration (net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE program). reqsk_timer_handler() clones the request socket with inet_reqsk_clone(), so that the old request socket and its clone share the same ireq_opt, then reqsk_migrate_reset() clears the pointer in the old one. Another cpu holding a reference on the old request socket can still be using these options (sending a SYNACK, or creating a child in tcp_v4_syn_recv_sock()) when the clone is freed, and tcp_v4_reqsk_destructor() also uses a plain kfree().

Readers already use RCU, and other paths replacing inet_opt (do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use kfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and tcp_v4_reqsk_destructor() as well.

IPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock() duplicates the options. tcp_v6_reqsk_destructor() has the same migration issue with ipv6_opt, which is only set by CALIPSO. This will be addressed in a separate patch.

References

12 sources
git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6
Source referenceLinux
git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5
Source referenceLinux
git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036
Source referenceLinux
git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a
Source referenceLinux
git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568
Source referenceLinux
git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2
Source referenceLinux
View 6 more references
git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936
Source referenceLinux
git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b
Source referenceLinux
www.openwall.com/lists/oss-security/2026/10/30/1
Security advisoryCVE
www.openwall.com/lists/oss-security/2026/10/30/6
Security advisoryCVE
www.openwall.com/lists/oss-security/2026/10/31/5
Security advisoryCVE
www.openwall.com/lists/oss-security/2026/11/03/1
Security advisoryCVE

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance · not supplied
Weakness classification · not supplied
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-98432

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Environment requirements

These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.

Linux · platform conditions

Any condition may hold

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 5.10.272

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 5.15.223

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 6.1.190

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 6.6.159

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 6.12.113

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 6.18.56

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 7.2.10

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.4

Before: 7.3

Applicability preview
[
  {
    "nodes": [
      {
        "operator": "OR",
        "negate": false,
        "cpeMatch": [
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "5.10.272"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "5.15.223"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "6.1.190"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "6.6.159"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "6.12.113"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "6.18.56"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "7.2.10"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.4",
            "versionEndExcluding": "7.3"
          }
        ]
      }
    ]
  }
]
Contributing organizations · 2
Linux

Assigning organization

2026-10-24
CVE

Additional data publisher

2026-11-03

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
  1. CVE · CVE-2026-98432

    Observed 2026-11-03T06:26:04.440Z · upstream updated 2026-11-03T06:08:32.425Z

    References changed

    before

    [
  "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
  "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
  "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036",
  "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a",
  "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568",
  "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2",
  "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936",
  "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b",
  "http://www.openwall.com/lists/oss-security/2026/10/30/1",
  "http://www.openwall.com/lists/oss-security/2026/10/30/6",
  "http://www.openwall.com/lists/oss-security/2026/10/31/5"
]

    after

    [
  "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
  "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
  "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036",
  "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a",
  "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568",
  "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2",
  "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936",
  "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b",
  "http://www.openwall.com/lists/oss-security/2026/10/30/1",
  "http://www.openwall.com/lists/oss-security/2026/10/30/6",
  "http://www.openwall.com/lists/oss-security/2026/10/31/5",
  "http://www.openwall.com/lists/oss-security/2026/11/03/1"
]
  2. CVE · CVE-2026-98432

    Observed 2026-10-31T22:21:03.543Z · upstream updated 2026-10-31T21:04:43.990Z

    References changed

    before

    [
  "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
  "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
  "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036",
  "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a",
  "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568",
  "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2",
  "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936",
  "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b",
  "http://www.openwall.com/lists/oss-security/2026/10/30/1",
  "http://www.openwall.com/lists/oss-security/2026/10/30/6"
]

    after

    [
  "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
  "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
  "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036",
  "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a",
  "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568",
  "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2",
  "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936",
  "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b",
  "http://www.openwall.com/lists/oss-security/2026/10/30/1",
  "http://www.openwall.com/lists/oss-security/2026/10/30/6",
  "http://www.openwall.com/lists/oss-security/2026/10/31/5"
]
  3. CVE · CVE-2026-98432

    Observed 2026-10-30T16:40:27.572Z · upstream updated 2026-10-30T15:05:31.932Z

    References changed

    before

    [
  "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
  "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
  "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036",
  "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a",
  "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568",
  "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2",
  "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936",
  "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b",
  "http://www.openwall.com/lists/oss-security/2026/10/30/1"
]

    after

    [
  "https://git.kernel.org/stable/c/b3b027ef0cd322bfa839b9aaf5b27551eea54cf6",
  "https://git.kernel.org/stable/c/95a8c8fa9f27dce64c40c41c062de7728bf34ab5",
  "https://git.kernel.org/stable/c/89b5b1eb7d633c33832b7ff2c02e19a144705036",
  "https://git.kernel.org/stable/c/742f73df544e03744f2981c467d6542fe8172a2a",
  "https://git.kernel.org/stable/c/11a03ce3c4a62d84c10ccdfe47f8075006498568",
  "https://git.kernel.org/stable/c/a47406c769f72c070386985488f1c4d057df86b2",
  "https://git.kernel.org/stable/c/26d4c36d318cffbbd160884a0e4cec0da4da4936",
  "https://git.kernel.org/stable/c/e3f33b0a1d89d738e2b913dab519226eaf76e15b",
  "http://www.openwall.com/lists/oss-security/2026/10/30/1",
  "http://www.openwall.com/lists/oss-security/2026/10/30/6"
]

Large field values are marked as truncated previews. Original source snapshots remain retained.

Showing up to 50 most recent observed changes.