CVE-2026-23419: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: net/rds: Fix circular locking dependency in rds_tcp_tune syzbot reported a circular locking dependency in rds_tcp_tune() where sk_net_refcnt_upgrade() is called while holding the socket lock: ====================================================== WARNING: possible circular locking dependency detected ====================================================== kworker/u10:8/15040 is trying to acquire lock: ffffffff8e9aaf80 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_cache_noprof+0x4b/0x6f0 but task is already holding lock: ffff88805a3c1ce0 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: rds_tcp_tune+0xd7/0x930 The issue occurs because sk_net_refcnt_upgrade() performs memory allocation (via get_net_track() -> ref_tracker_alloc()) while the socket lock is held, creating a circular dependency with fs_reclaim. Fix this by moving sk_net_refcnt_upgrade() outside the socket lock critical section. This is safe because the fields modified by the sk_net_refcnt_upgrade() call (sk_net_refcnt, ns_tracker) are not accessed by any concurrent code path at this point. v2: - Corrected fixes tag - check patch line wrap nits - ai commentary nits

Affected products

• Linux Linux Kernel: from 5.17.7, before 5.18 (fixed in 5.18); from 5.18.1, before 6.6.130 (fixed in 6.6.130); from 6.7, before 6.12.77 (fixed in 6.12.77); from 6.13, before 6.18.17 (fixed in 6.18.17); from 6.19, before 6.19.7 (fixed in 6.19.7); version 5.18 only; …

Published 2026-04-03. Last modified 2026-07-24.