CVE-2026-68290 (GCVE-0-2026-68290)

Vulnerability from cvelistv5 – Published: 2026-08-10 12:02 – Updated: 2026-08-17 05:02
VLAI
Title
rds: tcp: unregister sysctl before tearing down listen socket
Summary
In the Linux kernel, the following vulnerability has been resolved: rds: tcp: unregister sysctl before tearing down listen socket rds_tcp_exit_net() frees the per-netns RDS TCP listen socket via rds_tcp_kill_sock() before unregistering the per-netns sysctl table. Since rds_tcp_skbuf_handler() derives the netns from rtn->rds_tcp_listen_sock->sk, a concurrent sysctl write can race with netns teardown and dereference the freed socket/sk. KASAN reports the race as: BUG: KASAN: slab-use-after-free in rds_tcp_skbuf_handler+0x2aa/0x2e0 rds_tcp_skbuf_handler net/rds/tcp.c:721 proc_sys_call_handler fs/proc/proc_sysctl.c vfs_write fs/read_write.c __x64_sys_pwrite64 fs/read_write.c Fix this by unregistering the RDS TCP sysctl table before calling rds_tcp_kill_sock(). unregister_net_sysctl_table() prevents new sysctl handlers from starting and waits for in-flight handlers to finish, so the listen socket can then be released safely. The fix was tested against the linked reproducer.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: de8d6de0ee27be4b2b1e5b06f04aeacbabbba492 , < 80fffed08dc1c10e971066941d2daa56253f1552 (git)
Affected: 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c , < 16df2d154ec82e2f7e7585b4fa154751ba37729a (git)
Affected: 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c , < 3aa13fe0c1bb7bc5312f878e61523e5d8cf3f85d (git)
Affected: 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c , < 167e54c703ccd4fa028feb568b0d1002020cff86 (git)
Affected: 6.12.10 , < 6.12.101 (semver)
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Linux Linux Affected: 6.13
Unaffected: 0 , < 6.13 (semver)
Unaffected: 6.12.101 , ≤ 6.12.* (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/rds/tcp.c"
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrds: tcp: unregister sysctl before tearing down listen socket\n\nrds_tcp_exit_net() frees the per-netns RDS TCP listen socket via\nrds_tcp_kill_sock() before unregistering the per-netns sysctl table.  Since\nrds_tcp_skbuf_handler() derives the netns from\nrtn-\u003erds_tcp_listen_sock-\u003esk, a concurrent sysctl write can race with\nnetns teardown and dereference the freed socket/sk.\n\nKASAN reports the race as:\n\n  BUG: KASAN: slab-use-after-free in rds_tcp_skbuf_handler+0x2aa/0x2e0\n  rds_tcp_skbuf_handler              net/rds/tcp.c:721\n  proc_sys_call_handler              fs/proc/proc_sysctl.c\n  vfs_write                          fs/read_write.c\n  __x64_sys_pwrite64                 fs/read_write.c\n\nFix this by unregistering the RDS TCP sysctl table before calling\nrds_tcp_kill_sock().  unregister_net_sysctl_table() prevents new sysctl\nhandlers from starting and waits for in-flight handlers to finish, so\nthe listen socket can then be released safely. The fix was tested\nagainst the linked reproducer."
        }
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        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/167e54c703ccd4fa028feb568b0d1002020cff86"
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    "datePublished": "2026-08-10T12:02:23.425Z",
    "dateReserved": "2026-07-30T09:28:09.380Z",
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    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-08-14T08:49:10+00:00",
      "cve": "CVE-2026-68290",
      "id": "CVE-2026-68290",
      "initial_release_date": "2026-08-10T12:02:23.425000+00:00",
      "product_status:known_affected": "106",
      "product_status:known_not_affected": "170",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Kernel: Use-after-free vulnerability in RDS TCP can lead to system instability",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68290.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • 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.


Detection rules are retrieved from Rulezet.