net/rds: Fix circular locking dependency in rds_tcp_tune_CVE-2026-23419

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: Fix circular locking dependency in rds_tcp_tune\n\nsyzbot reported a circular locking dependency in rds_tcp_tune() where\nsk_net_refcnt_upgrade() is called while holding the socket lock:\n\n======================================================\nWARNING: possible circular locking dependency detected\n======================================================\nkworker/u10:8/15040 is trying to acquire lock:\nffffffff8e9aaf80 (fs_reclaim){+.+.}-{0:0},\nat: __kmalloc_cache_noprof+0x4b/0x6f0\n\nbut task is already holding lock:\nffff88805a3c1ce0 (k-sk_lock-AF_INET6){+.+.}-{0:0},\nat: rds_tcp_tune+0xd7/0x930\n\nThe issue occurs because sk_net_refcnt_upgrade() performs memory\nallocation (via get_net_track() -> ref_tracker_alloc()) while the\nsocket lock is held, creating a circular dependency with fs_reclaim.\n\nFix this by moving sk_net_refcnt_upgrade() outside the socket lock\ncritical section. This is safe because the fields modified by the\nsk_net_refcnt_upgrade() call (sk_net_refcnt, ns_tracker) are not\naccessed by any concurrent code path at this point.\n\nv2:\n  - Corrected fixes tag\n  - check patch line wrap nits\n  - ai commentary nits",
    "published": "2026-04-03T13:24:23.958Z",
    "modified": "2026-04-27T14:02:15.157Z",
    "type": "cve",
    "title": "net/rds: Fix circular locking dependency in rds_tcp_tune",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/8babb271403378ba6836f6c8599c5313d0e2355d\nhttps://git.kernel.org/stable/c/8519e6883a942e510f33a0e634e27bcc3a844a40\nhttps://git.kernel.org/stable/c/6ce948fa54599f369ff7fe8b793a6aae4b0762b2\nhttps://git.kernel.org/stable/c/026bbaeeab9e04534ee58882b6447300629b42f6\nhttps://git.kernel.org/stable/c/6a877ececd6daa002a9a0002cd0fbca6592a9244",
    "id": "CVE-2026-23419",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 3a58f13a881ed351198ffab4cf9953cf19d2ab3a\nLinux Linux 3a58f13a881ed351198ffab4cf9953cf19d2ab3a\nLinux Linux 3a58f13a881ed351198ffab4cf9953cf19d2ab3a\nLinux Linux 3a58f13a881ed351198ffab4cf9953cf19d2ab3a\nLinux Linux 3a58f13a881ed351198ffab4cf9953cf19d2ab3a\nLinux Linux 2a6efabed754c9dcf27e6def71317b374f58a852\nLinux Linux 5.18",
    "sourceHref": "",
    "cvss": {
        "score": 7.5,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
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        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "3a58f13a881ed351198ffab4cf9953cf19d2ab3a",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
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    "ai_version": "",
    "ai_score": 0
}