{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23419", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:46.014Z", "datePublished": "2026-04-03T13:24:23.958Z", "dateUpdated": "2026-08-05T12:21:36.998Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:21:36.998Z" }, "descriptions": [ { "lang": "en", "value": "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" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - RDS/TCP creates a listener on TCP port 16385, and an unauthenticated remote TCP connection reaches rds_tcp_accept_one() and rds_tcp_tune() before protocol-level validation. A local AF_RDS path also exists, but the highest reasonable vector is network.\nAC:L - The attacker can repeatedly trigger the vulnerable lock ordering by opening RDS/TCP connections; no special packet format, credentials, or attacker-uncontrolled race is needed to reach the bad allocation-under-socket-lock path. Applying the higher-severity rule, this is Low complexity.\nPR:N - The network accept path requires no local account, capabilities, or RDS authentication before rds_tcp_tune() is invoked. Remote reachability to the RDS/TCP listener is sufficient in a reasonable affected deployment.\nUI:N - No victim user action is required. The attacker can initiate the connection directly.\nS:U - The issue affects kernel locking within the same host security authority. It does not cross a VM, container, IOMMU, or other separate security scope boundary.\nC:N - The bug is a circular locking dependency involving sk_lock, sk_net_refcnt_upgrade(), ref_tracker allocation, and fs_reclaim. It does not expose kernel memory or create a read primitive.\nI:N - There is no memory corruption or write primitive; the fix only moves a refcount-tracker allocation outside the socket lock. Integrity is not directly impacted.\nA:H - The lock inversion can lead to a kernel deadlock or system hang, and syzbot reported it as a possible deadlock in the RDS accept worker. Kernel deadlock is High availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/rds/tcp.c" ], "versions": [ { "version": "3a58f13a881ed351198ffab4cf9953cf19d2ab3a", "lessThan": "8babb271403378ba6836f6c8599c5313d0e2355d", "status": "affected", "versionType": "git" }, { "version": "3a58f13a881ed351198ffab4cf9953cf19d2ab3a", "lessThan": "8519e6883a942e510f33a0e634e27bcc3a844a40", "status": "affected", "versionType": "git" }, { "version": "3a58f13a881ed351198ffab4cf9953cf19d2ab3a", "lessThan": "6ce948fa54599f369ff7fe8b793a6aae4b0762b2", "status": "affected", "versionType": "git" }, { "version": "3a58f13a881ed351198ffab4cf9953cf19d2ab3a", "lessThan": "026bbaeeab9e04534ee58882b6447300629b42f6", "status": "affected", "versionType": "git" }, { "version": "3a58f13a881ed351198ffab4cf9953cf19d2ab3a", "lessThan": "6a877ececd6daa002a9a0002cd0fbca6592a9244", "status": "affected", "versionType": "git" }, { "version": "2a6efabed754c9dcf27e6def71317b374f58a852", "status": "affected", "versionType": "git" }, { "version": "5.17.7", "lessThan": "5.18", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/rds/tcp.c" ], "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.77", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.17", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.7", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.77" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.19.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.0" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17.7" } ] } ] } ], "references": [ { "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" } ], "title": "net/rds: Fix circular locking dependency in rds_tcp_tune", "x_generator": { "engine": "bippy-1.2.0" } } } }