{"id":"CVE-2026-23419","title":"net/rds: Fix circular locking dependency in rds_tcp_tune","summary":"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 …","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < ce5be6703afd2ac2ff7dabd397137d71d22d4bc3","Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 8babb271403378ba6836f6c8599c5313d0e2355d","Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 8519e6883a942e510f33a0e634e27bcc3a844a40","Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 6ce948fa54599f369ff7fe8b793a6aae4b0762b2","Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 026bbaeeab9e04534ee58882b6447300629b42f6","Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 6a877ececd6daa002a9a0002cd0fbca6592a9244","Linux 2a6efabed754c9dcf27e6def71317b374f58a852","Linux >= 5.17.7 < 5.18","Linux 5.18"],"published":"2026-04-03","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:24:06.599Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23419","references":[{"url":"https://git.kernel.org/stable/c/ce5be6703afd2ac2ff7dabd397137d71d22d4bc3"},{"url":"https://git.kernel.org/stable/c/8babb271403378ba6836f6c8599c5313d0e2355d"},{"url":"https://git.kernel.org/stable/c/8519e6883a942e510f33a0e634e27bcc3a844a40"},{"url":"https://git.kernel.org/stable/c/6ce948fa54599f369ff7fe8b793a6aae4b0762b2"},{"url":"https://git.kernel.org/stable/c/026bbaeeab9e04534ee58882b6447300629b42f6"},{"url":"https://git.kernel.org/stable/c/6a877ececd6daa002a9a0002cd0fbca6592a9244"}],"tags":["cve.org"],"epss":0.00193,"epssPercentile":0.09075,"ingestedAt":"2026-11-05T15:02:32.208Z","slug":"CVE-2026-23419","body":"## Overview\n\nIn 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\n\n## Affected\n\n- `Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < ce5be6703afd2ac2ff7dabd397137d71d22d4bc3`\n- `Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 8babb271403378ba6836f6c8599c5313d0e2355d`\n- `Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 8519e6883a942e510f33a0e634e27bcc3a844a40`\n- `Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 6ce948fa54599f369ff7fe8b793a6aae4b0762b2`\n- `Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 026bbaeeab9e04534ee58882b6447300629b42f6`\n- `Linux >= 3a58f13a881ed351198ffab4cf9953cf19d2ab3a < 6a877ececd6daa002a9a0002cd0fbca6592a9244`\n- `Linux 2a6efabed754c9dcf27e6def71317b374f58a852`\n- `Linux >= 5.17.7 < 5.18`\n- `Linux 5.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}