In the Linux kernel, the following vulnerability has been resolved:
netlink: avoid infinite retry looping in netlink_unicast()
netlink_attachskb() checks for the socket's read memory allocation
constraints. Firstly, it has:
rmem < READ_ONCE(sk->sk_rcvbuf)
to check if the just increased rmem value fits into the socket's receive
buffer. If not, it proceeds and tries to wait for the memory under:
rmem + skb->truesize > READ_ONCE(sk->sk_rcvbuf)
The checks don't cover the case when skb->truesize + sk->sk_rmem_alloc is
equal to sk->sk_rcvbuf. Thus the function neither successfully accepts
these conditions, nor manages to reschedule the task - and is called in
retry loop for indefinite time which is caught as:
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 0-....: (25999 ticks this GP) idle=ef2/1/0x4000000000000000 softirq=262269/262269 fqs=6212
(t=26000 jiffies g=230833 q=259957)
NMI backtrace for cpu 0
CPU: 0 PID: 22 Comm: kauditd Not tainted 5.10.240 #68
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc42 04/01/2014
Call Trace:
dump_stack lib/dump_stack.c:120
nmi_cpu_backtrace.cold lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace lib/nmi_backtrace.c:62
rcu_dump_cpu_stacks kernel/rcu/tree_stall.h:335
rcu_sched_clock_irq.cold kernel/rcu/tree.c:2590
update_process_times kernel/time/timer.c:1953
tick_sched_handle kernel/time/tick-sched.c:227
tick_sched_timer kernel/time/tick-sched.c:1399
__hrtimer_run_queues kernel/time/hrtimer.c:1652
hrtimer_interrupt kernel/time/hrtimer.c:1717
__sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113
asm_call_irq_on_stack arch/x86/entry/entry_64.S:808
netlink_attachskb net/netlink/af_netlink.c:1234
netlink_unicast net/netlink/af_netlink.c:1349
kauditd_send_queue kernel/audit.c:776
kauditd_thread kernel/audit.c:897
kthread kernel/kthread.c:328
ret_from_fork arch/x86/entry/entry_64.S:304
Restore the original behavior of the check which commit in Fixes
accidentally missed when restructuring the code.
Found by Linux Verification Center (linuxtesting.org).
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it