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

What is CVE-2026-23419?

CVE-2026-23419 is a high-severity vulnerability in Linux kernel, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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

Weakness: CWE-667

Which versions are affected by CVE-2026-23419?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23419?

Apply the vendor's patch.

Is CVE-2026-23419 being exploited?

There is no known exploitation of CVE-2026-23419 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-23419, DEBIAN-CVE-2026-23419, GHSA-x244-gjj6-jc73, ROOT-OS-DEBIAN-12-CVE-2026-23419, ROOT-OS-DEBIAN-13-CVE-2026-23419, ROOT-OS-UBUNTU-2404-CVE-2026-23419 and 1 more.